System having plurality of docking unit receptacles for transmitting data between plurality of portable data entry terminals in local area network with a central controller

ABSTRACT

In an exemplary embodiment, portable data devices can be coupled with a local area network at any of a multiplicity of points and integrated into the system. The preferred system is highly flexible and closely adaptable to changing needs of an individual user. For example, unitary multiple docking devices each receiving a plurality of hand-held computerized data terminals may be chained in a series to a single primary controller which may have a further LAN channel including an auxiliary unit which may supply charging power to a further series of multiple docking devices, added to the system as needed. A preferred auxiliary unit is capable of handling two-way communication without the provision of a direction control line in the channel. A preferred LAN system may have unitary printed circuit boards or other rigid network pathways provided with multiple docking receptacles. The control for the LAN system will automatically establish identities for randomly added devices.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 08/250,827 (Attorney Docket No. DN36919XB), filed May 31, 1994,by Robert J. Traeger, abandoned, which is itself a continuation of U.S.patent application Ser. No. 07/921,408, filed Jul. 31, 1992, now U.S.Pat. No. 5,317,691, which itself is a continuation of U.S. patentapplication Ser. No. 07/759,807 filed Sep. 16, 1991, abandoned, whichitself is a continuation of U.S. patent application Ser. No. 07/400,833,filed Aug. 30, 1989, abandoned, which itself is a continuation-in-partof U.S. patent application Ser. No. 07/347,298, filed May 2, 1989,abandoned, and a continuation-in-part of U.S. patent application Ser.No. 07/347,849, filed May 3, 1989, abandoned. The aforementionedapplications are hereby incorporated herein by reference in theirentirety.

BACKGROUND OF THE INVENTION

In the data capture field, there are many applications where hand-helddata terminals should be of rugged construction so as to survive roughhandling. Many operators are not inclined toward painstaking or precisemanipulations. An example is in the use of RF data capture terminals onforklift trucks in factories and warehouses where items to betransported are identified by bar codes. Other examples are found in thefield of route delivery and direct store delivery where many items arehandled and the terminal means automates the accounting function. Evenin applications where bar code data is transmitted on-line to a centralstation, it may be desirable for hand-held terminals to be inserted intodocking apparatus for the interchange of data signals e.g. the loadingof scheduling information or the like into the terminal at the beginningof a working shift. Further where terminal means has memory capacity foraccumulating data during a delivery operation or the like, it may bedesirable for such data to be transferred to a printer so that a hardcopy may be produced. In cases where rechargeable batteries are used,the docking apparatus may provide for the recharging of such batteriesat the same time as data communication is taking place.

It is conceived that it would be highly advantageous to provide a datacommunication system with docking apparatus adaptable to a wide range ofterminal means, and which furthermore could be quickly and simply loadedin a relatively foolproof manner, and without requiring attention andcare from operators engaged in physically demanding and arduous workroutines.

SUMMARY OF THE INVENTION

Accordingly, it is an important object of the present invention toprovide a data communication system wherein components can be readilydetached for portable operation. A further object resides in theprovision of such a data communication system wherein multiple devicesmay be connected at different locations on a local area network andintegrated into a data communication system.

In a presently preferred configuration for communication with portabledata capture terminals, a local area network (LAN) has the followingcharacteristics:

(1) The LAN is configured so that multiple devices may be connectedsimultaneously.

(2) The LAN provides reliable two-way data communication.

(3) The LAN may have a total length up to hundreds of feet.

(4) Any connected device may be inactive or off without having an effecton the other devices.

Power for operation of the portable data terminal is provided by theinternal terminal batteries when used portably and by the docking systemwhen the terminal is placed in a terminal receptacle thereof. Further,the terminal batteries may receive charge while the terminal isoperating from the system power so that full battery capacity isavailable when portable operation is again required.

The present invention relates particularly to data communication systemsfor portable data terminal means which are to be held in one hand duringdata capture operation; however the invention is also applicable toportable data terminal means which may be mounted e.g. on a belt or e.g.on a vehicle during data capture operation. The data terminal meanspreferably will be of size and weight to be held in one hand, eventhough not so held during data capture operation. Also the data terminalmeans may be provided with batteries so as to be capable of portableoperation, and such batteries may be rechargeable.

In a typical case, the portable data terminal means will have userinterface means such as a manually operated data input (e.g. a keyboard)and/or a data output (e.g. a liquid crystal display), and will containdata storage means for the storage of programming instructions and/orprogram data, and/or for the storage of data capture information.

In accordance with an important aspect of the present disclosure, adocking apparatus removably receives portable data terminal means forpurposes of data communication e.g. with a host computer and/or for therecharging of rechargeable batteries, and is so configured that theterminal means may have electrical contact pad means generally flushwith the exterior of the terminal means. Preferably an abutting typeengagement between the terminal contact pad means and cooperatingelectrical contact means of the docking apparatus is used for eachelectrical connection which is required at the docking apparatus, andthe typical pin and socket type docking connections are entirelyavoided.

In accordance with another aspect of the invention the same basicdocking structure may be provided with greater or lesser numbers ofcontact positions. For example, one type of hand-held terminal intendedfor on-line RF communication with a host computer may have six contactpads for coupling with a local area network, and may have a nineposition electrical connector for compatibility with an earlier type ofinterface system requiring interfitting of pin and socket connectors;another type of hand-held terminal designed for route accountingapplications may have e.g. twelve external contact pads and be intendedfor interfacing only with systems having provision for open abutmenttype interconnection.

A further object is to provide an expandable docking network which isclosely adaptable to changing needs of various customers.

A particular feature resides in the provision of auxiliary units forexpanding the local area network of a docking system without requiring adirection control line for the signal communication repeater system.

A further object is to provide a particularly economical and reliablemultidocking subsystem which may be quickly and conveniently configuredinto a larger network as required.

A unique feature resides in a multipoint coupling with a local areanetwork formed directly on a printed circuit board or other rigidelectrical pathway of this type. For example, a six unit dockingsubsystem may be implemented as a single wall-or bench-mounted entity,and one or two printed circuit boards may directly carry the local areanetwork pathways to all six docking points. In a most preferredembodiment both signal and power pathways traverse the subsystem fromend to end, and further subsystems may be chained therewith at eitherend as desired.

Other objects, features and advantages will be apparent from thefollowing detailed description, taken in connection with theaccompanying drawings, and from the individual features andrelationships of the respective appended claims.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

FIG. 1 is a perspective view of a preferred docking unit for use in thepresent invention.

FIG. 2 is a partial enlarged perspective view of the contact end of ahand-held device of the type shown in FIG. 1.

FIG. 3 is an enlarged view of the multiple contact subassembly formingpart of the terminal receptacle means of FIG. 1.

FIG. 4 is a front elevation of the embodiment of the docking unit shownin FIG. 1 with portions cut away.

FIG. 5 is a view in section along lines 5--5 of FIG. 4.

FIG. 6 is a perspective view of a multidocking apparatus for use in anembodiment of the invention, with a hand-held device in one of theterminal receptacles.

FIG. 7 is a frontal elevational view of the multidocking apparatus ofFIG. 6.

FIG. 8 is a rear elevational view of the docking apparatus of FIGS. 6and 7.

FIG. 9 is a left end elevational view of the docking apparatus as seenin FIG. 7.

FIG. 10 is a top plan view of the docking apparatus as shown in FIG. 7.

FIG. 11 is a bottom plan view of the docking apparatus of FIG. 7.

FIG. 12 is a frontal elevational view of a single docking unit such asshown in FIG. 1.

FIG. 13 is a left side elevational view of the docking unit of FIG. 12.

FIG. 14 is a top plan view of the docking unit of FIG. 12.

FIG. 15 is a bottom plan view of the docking unit of FIG. 12.

FIG. 16 is a rear elevational view of the docking unit of FIG. 12.

FIG. 17 is a front elevational view of a network controller unit forcommunication with the docking units of FIGS. 1 through 16.

FIG. 18 is a left side elevational view of the network controller ofFIG. 17.

FIG. 19 is a top plan view of the network controller of FIG. 17.

FIG. 20 is a right side elevational view of the network controller ofFIG. 17.

FIG. 21 is a rear elevational view of the network controller of FIG. 17.

FIG. 22 is a bottom plan view of the network controller of FIG. 17.

FIG. 23 is a somewhat diagrammatic partially exploded frontalelevational view showing multidocking apparatus according to FIGS. 6 and7, but with certain parts broken away to illustrate significant featuresof internal construction.

FIG. 24 is a somewhat diagrammatic left side elevational view of thestructure of FIG. 23 with parts separated from each other to indicatedetails of internal construction and assembly.

FIG. 25 is a somewhat diagrammatic front elevational view of the printedcircuit boards and contact assemblies associated with the multidockingapparatus of FIG. 23.

FIG. 26 is a top plan view of the solder sides of the printed circuitboards utilized in the multidocking apparatus of FIG. 23.

FIG. 27 is a somewhat diagrammatic exploded elevational view forillustrating constructional details associated with the printed circuitboard arrangement of FIG. 25.

FIG. 28 shows a typical network configuration involving multidockapparatus such as shown in FIGS. 6 through 10 and 23 through 27, andwhich may utilize a network controller such as illustrated in FIGS. 17through 22.

FIG. 28A illustrates a communications system relating to a single dockunit such as shown in FIGS. 1 through 5 and 12 through 16.

FIGS. 29 and 29A show circuitry for an auxiliary power unit which may beutilized as illustrated in FIG. 28.

FIGS. 30A and 30B together show a block diagram of a local area networkcontroller such as may be utilized in the network configuration of FIG.28, FIG. 30B being a continuation of FIG. 30A to the right.

FIG. 31 shows an exemplary implementation for the PAL component of FIG.30A.

FIGS. 32A and 32B show a preferred implementation for the auxiliarypower unit of FIG. 28.

FIG. 33 shows an exemplary implementation for the RS232 interfacecomponents of FIG. 30B.

FIGS. 34A, 34B and 34C show an exemplary implementation for the portselect and RS485 interface components of FIG. 30B.

FIGS. 35A and 35B show an exemplary implementation for the plus twelvevolt regulator and plus five volt DC/DC converter components of FIG.30B.

FIGS. 36A, 36B and 36C show an exemplary circuit for the RAM controllercomponent of FIG 30A.

FIGS. 37A through 37F show circuit details related to the EPROMcomponent, the microprocessor component, the latch component and thereal time clock of FIG. 30A, and related components, FIG. 37B being acontinuation of FIG. 37A to the right, FIG. 37C being a continuation ofFIG. 37B to the right and sharing a vertical segment of the control bustherewith, FIG. 37D being a continuation of FIG. 37A in the downwarddirection, FIG. 37E being a continuation of FIG. 37B in the downwarddirection and a continuation of FIG. 37D to the right, and FIG. 37Fsharing a vertical segment of the control bus with FIG. 37E and thusbeing a continuation of FIGS. 37B and 37C in the downward direction anda continuation of FIG. 37E to the right.

FIGS. 38A through 38E show the serial communications controllercomponents of FIG. 30B in a preferred implementation and show additionalcircuitry such as the keyboard encoder component and the disk drivecontroller of FIG. 30A, FIG. 38B being a continuation of FIG. 38A to theright, FIG. 38C being a continuation of FIG. 38A in a downwarddirection, FIG. 38D being a continuation of FIG. 38B in a downwarddirection and a continuation of FIG. 38C to the right, and FIG. 38Ebeing a continuation of FIG. 38B in a downward direction and acontinuation of FIG. 38D to the right.

FIG. 39 is a block diagram of a similar type to FIG. 29, but showing apreferred embodiment of the auxiliary power unit whereby the directioncontrol line of FIG. 29 can be eliminated. (FIGS. 32A and 32B show adetailed exemplary implementation of the auxiliary power unit of FIG.39.)

FIG. 40 illustrates the manner in which a preferred docking system canbe expanded using auxiliary power units such as shown in FIG. 39.

FIG. 41 shows exemplary conductor paths for the case of multidockprinted circuit boards as indicated in FIGS. 25 and 26, such printedcircuit boards each having three associated docking unit couplingpositions.

FIG. 42 is a plan view of the solder side of a printed circuit boardimplementing the circuitry of FIG. 41.

FIG. 43 is a plan view of the copper side of the printed circuit boardof FIG. 42, and showing the printed circuit board of FIG. 42 wheninverted end for end.

DETAILED DESCRIPTION Description of FIGS. 1-6

Referring now to the drawings, FIG. 1 discloses a preferred embodimentof single docking unit 2 in a perspective view, showing a data entryterminal 4 of a type insertable therein. Data entry terminal 4 isprovided with an elongated housing 6 having a front wall 8 generallyorthogonally positioned to end walls 16 and 18. A keypad 10 and visualdisplay 12 are provided on front wall 8 of housing 6. It is intendedthat data entry terminal 4 is a portable, preferably hand-held, datacollection device which may be carried with the user such that the usermay enter data to be collected either by activation of the keys ofkeypad 10 or by other means, such as through bar code readingaccessories, which are not illustrated in the drawings. Data entryterminal 4 may provide data or instructions to the user by way ofdisplay 12, and/or display 12 may display to the user the data which isbeing entered through the keypad or other input means which may be used.Data entry terminal 4 may also be equipped to electromagneticallycommunicate by transmitted waves with other devices to gather andtransmit data.

Devices such as data entry terminal 4 require electrical power tooperate, such power generally being provided by rechargeable batteriescontained within housing 6. Because such batteries become dischargedwith use, it is desirable for data entry terminal 4 to be electricallychargeable by external means.

As seen in the preferred embodiment of FIG. 1, docking unit 2 comprisesa generally upstanding terminal receptacle means 20 into which dataentry terminal 4 is insertable. Receptacle 20 comprises opposingsidewalls 22 and 24 which are interconnected by rear wall 26. Front wall28 of receptacle 20 is substantially shorter than rear wall 26 therebyavoiding interference with the keypad 10 of data entry terminal 4. Abottom wall 30 of receptacle 20 interconnects with sidewalls 22 and 24and with front wall 28 and rear wall 26. Contact members 32 projectthrough an aperture in bottom wall 30. Rail 34 (see also FIG. 4) extendsinwardly from rear wall 26, so as to engage the back of data entryterminal 4 as it is inserted into a loading channel 36, thereby guidingthe data entry terminal 4 into proper position relative to contactmembers 32. Cooperating frontal terminal guide ribs such as 37, FIG. 1,further serve to define the loading channel 36.

Receptacle 20 may be carried by a supporting framework 40 which in turnmay be wall or table mounted by means of a bracket 42.

Bracket 42 is provided with a generally upstanding plate 48 and anintegral base 46. Slotted opening 44 is provided in plate 48 to allowhanging of the docking unit upon a vertical surface if desired. Base 46provides a structure for fastening the docking unit to a horizontalworkbench or shelf, if preferred.

Plate 48 of support 42 is provided with opening 49 to receive plug meansof a typical telephone wall mounting plate. Slotted opening 44 and slot47 of plate 48 are disposed to receive large-headed mounting studstypical of telephone wall mounting plates. Thus a user may leave dockingunit 2 attached to a wall at a telephone wall plate and may attachtelephone cabling through opening 49 to modulator-demodulator meanswhich may interconnect with data entry terminal 4. When dataintercommunication with a data collection device, or recharging thereofis desired, the device may be placed within the docking unit 2 as ithangs from a wall, mounted to a telephone wall plate if desired.

Referring now to FIGS. 4 and 5, the structure of a preferred embodimentof docking unit 2 can better be visualized. Contact elements 32 arearranged in spaced apart insulated fashion and are mounted at bottomwall 30 of receptacle 20. Offset part 25 of the rear wall 26 overhangsrear wall 41 of frame 40. Detents 50 and 52 are carried by tabs 54 whichare integral with rear wall 26 at sloped region 27 thereof. Thisconstruction allows tabs 54 to deflect relative to rear wall 26. Detents50 and 52 comprise mating elements for indentations formed in the rearof housing 6 of data entry terminal 4 and are positioned on rear wall 26such that mating engagements with indentations on data entry terminal 4are achieved when data entry terminal 4 is fully seated withinreceptacle 20. Electrical connector 76 provides an interconnectionjunction between circuit board 48 and external means and in thepreferred embodiment comprises a pin-containing shell housing well knownas a DB-9 connector.

Referring to FIG. 3, a plurality of contact elements 32 are deployedwithin a contact block 70 of insulating material. In FIG. 3, one contactelement 32 is displaced from its position on block 70 for illustrationof detail. Each contact element 32 comprises a formed conductive striphaving a first leg 60 and a second leg 62. Leg 62 is provided with agenerally U-shaped area 64 therealong. First leg 60 and second leg 62are formed in generally parallel relationship separated by a reversebend 66. Contact elements 32 are constructed of electrically conductivematerial with sufficient resilience such that the second leg 62 willreturn to its generally parallel relationship to first leg 60 when notsubjected to deflective force.

Each contact element 32 is fitted into contact receiving block 70 suchthat contact elements 32 are spaced apart in generally parallelinsulated relationship with U-shaped sections 64 projecting upwardly.The second legs 62 including U-shaped sections 64 are free to bedeflected somewhat downward when contact elements 32 are positionedwithin contact receiving block 70. First leg 60 of contact element 32 isprovided with a protrusion 63 projecting below lower surface 61 thereof,said protrusion 63 establishing electrical contact with a conductivearea upon circuit board 48, FIG. 5, to which contact receiving block 70is mounted.

Referring now in particular to FIG. 5, it can be seen that contactreceiving block 70 is stationed below bottom wall 30 of receptacle 20,with the U-shaped sections 64 of contact elements 32 normally projectingthrough opening 72 of bottom wall 30.

Frame 40 carries receptacle 20, being secured thereto by screw 74.Bracket 42 is secured to frame 40 at angle pieces 43 and 45 and isshaped to afford a convenient recline to frame 40. It can be seen thatbracket 42 may be mounted by appropriate means to a vertical structure,or to a horizontal structure at its base 46.

FIG. 2 discloses, from the rear, the lower end 17 of the hand-held dataentry terminal 4 of FIG. 1. Indentations 56 and 58 are provided on awear plate 55 at the back of data entry terminal 4 and are disposed toreceive detents 50 and 52 respectively when data entry terminal 4 isinserted in receptacle 20 and seated upon bottom wall 30 thereof. Aplurality of contact pads 80 are positioned upon end wall 18 of dataentry terminal 4. When data entry terminal 4 is properly positioned inreceptacle 20, contact pads 80 of data entry terminal 4 engage contactelements 32 at U-shaped sections 64 thereof in abutting pressureengagement. The engagement of contact pads 80 with contact elements 32provides a substantial deflection of the legs 62 of the contact elementsrelative to legs 60, and results in substantial contact pressure betweeneach U-shaped section 64 and the associated contact pad 80. Thedeflection of legs 62 is limited by stop 82, which can be best seen inFIG. 5.

The employment of detents 50 and 52 in cooperation with indentations 56and 58 permits receptacle 20 to be disposed in other than generallyvertical orientation while still allowing secure retention of data entryterminal 4 in frame 20 with reliable interengagement of contact pads 80of data entry terminal 4 with contact elements 32 of the receptacle.

FIG. 6 discloses a multidocking unit wherein a plurality of receptacles20 are mounted within an elongated frame 140. In the embodiment shownthere are six receptacles 20. A data entry terminal 4 may be placed ineach of the receptacles 20 of the unit of FIG. 6, such that six dataentry terminal units may be recharged and/or integrated with a datacollection system at one time. Each data entry terminal 4 may beselectively positioned in any of the receptacles 20 independently of anyplacement of other data entry terminals in any other receptacle 20.Frame 140 is supported at a slight recline by a bracket 142 whichcomprises base 146 and upstanding wall 148. Mounting means 102 isoptionally available to secure bracket 142 to a vertical structure, ifdesired.

OPERATION OF THE EMBODIMENT OF FIGS. 1-5

As the need arises to recharge the internal batteries of one or moredata entry terminal 4, or to feed data to or collect data, from saiddata entry terminal 4, the data entry terminal 4 may be placed in areceptacle 20 such that the contact pads 80 of data entry terminal 4engage and depress the resilient legs 62 of contact elements 32 ofreceptacle 20. Since contact pads 80 and contact elements 32 areelectrically conductive, the engagement of a contact pad 80 with acontact element 32 provides a completed electrical pathway such thatelectrical charging and electrical communication between the dockingsystem 2 and data entry terminal 4 may be accomplished.

Detents 50 and 52 of rear wall 26 of receptacle 20 engage matingindentations 56 and 58 on the rear of data entry terminal 4 such thatsufficient mechanical rigidity is achieved between data entry terminal 4and receptacle 20 to maintain firm pressure engagement between contactpads 80 of data entry terminal 4 and contact elements 32 of receptacle20.

Bracket 42 of docket unit 2 may be mounted to a vertical wall over atelephone mounting bracket having vertically spaced apart studs and atelephone jack which remains accessible through opening 49 of plate 48of bracket 42.

Once insertion of data entry terminal 4 is completed within receptacle20, recharging of batteries and intercommunication of the data entryterminal with outside computing facilities may be achieved.

Reference is made to a copending application of Patrick H. Davis, U.S.Ser. No. 07/327,660 filed Mar. 23, 1989, Attorneys Docket No. 36504X,which contains description and claims relating to FIGS. 1 to 6, and theentire disclosure of this copending application including the drawingsis hereby incorporated herein by reference.

Description of FIGS. 7-11

FIGS. 7 to 11 correspond generally with figures one to five of a pendingdesign patent application U.S. Ser. No. 07/303,557 filed Jan. 27, 1989,Attorneys Docket No. 36504 now abandoned, and the entire disclosureincluding the drawings of U.S. Ser. No. 07/303,557 is incorporatedherein by reference.

FIG. 7 shows a multidock system 100 with a series of receptacle modules101-106 corresponding to the receptacles 20 of FIGS. 1 and 6. Eachreceptacle may be identical to the receptacle 20 of FIG. 1, and beprovided with detents 50, 52 as in FIGS. 4-5.

FIG. 9 shows a left end cap 111 for the system 100, and right hand endcap 112, FIG. 7 may be a mirror image of left end cap 111.

As seen in FIGS. 8 and 9, the system 100 may be provided with a mountingbracket 120, with feet such as 121, 122, FIG. 7, and 123, 124, FIG. 8,for facilitating mounting of an horizontal support surface of a bench orthe like. For wall mounting, shoulder rivets 125-128, FIG. 8, areprovided.

FIG. 10 shows the sets of spring fingers, 141-146, corresponding tocontacts 32, FIG. 3, for the respective receptacle modules 101-106.

Since each of the receptacle modules is designed to function the same asthe receptacle 20 of FIG. 1, a further description of FIGS. 7 to 11would be superfluous. A major advantage of the multidock system is thatit may be formed of parts identical to parts of the receptacle 20 shownin FIGS. 1-5.

Description of FIGS. 12-16

FIGS. 12 to 16 show the general subject matter of figures six to ten ofthe incorporated design patent application U.S. Ser. No. 07/303,557.

FIGS. 12 to 16 may illustrate a single dock assembly which is identicalto that of FIGS. 1 to 5 and accordingly the same reference numerals havebeen applied. End caps 111', 112' may be of the same construction asparts 111, 112, FIGS. 7-9. FIGS. 12 to 16 further show a single dockstand 160, which may have feet 161-164 for accommodating mounting of thesingle dock on a horizontal surface, e.g. of a desk or table. Slots 171,172, FIG. 16, accommodate wall mounting of the assembly.

Description of FIGS. 17-22

FIGS. 17 to 22 show a network controller unit 200 which may beassociated with the multidock assembly 100, FIGS. 7 to 11, forfurnishing charging potential to the terminals in the respectivereceptacle modules such as 101-106. The controller 200 may also, forexample, control communication between the respective terminals and ahost computer system.

The controller 200 is shown as comprising a base 201 and cover 202forming a housing for the electrical components. A feet bracket 203 hasfront feet 206, FIG. 20, and 207, FIG. 18, while the base 201 directlymounts rear feet 208, 209. Wall mounting is accommodated by shoulderedrivets 211, 212. The cover has a keyboard 220 and a display 221 at thefront thereof. A loading slot 224, FIG. 18, may be at the left side forreceiving a floppy disk. A cooling fan outlet 226 is shown in FIG. 20.

A power receptacle 230 and a power control switch 231 are indicated inFIG. 18. FIG. 21 shows a bracket 234 for mounting six D-sub typeconnectors.

The internal structure and operation of the controller 200 will bedescribed in detail hereinafter.

Description of FIGS. 23-27

FIGS. 23 to 27 show a preferred electrical configuration for themultidock arrangement of FIGS. 6 and 7 to 11.

As shown in FIG. 23, printed circuit boards 301, 302 may each extendcontinuously through a set of three receptacle modules, i.e. board 301extends through modules 101-103 and board 302 is associated with modules104-106. The two boards 301, 302 may be interconnected by a flex cable303. The set of six modules of a multidock unit may be coupled with thecontroller unit 200 by means of one of two end connector receptacles311, 312, FIG. 25. The other end connector receptacle may connect thesystem to a further multidocking unit, for example.

In the embodiment of FIGS. 23-27, a single continuous receptacle supportplate 420 may have the receptacle modules 101-106 secured therewith bymeans of respective hooks such as 421, FIG. 24, which are formedintegrally with the rear walls of the modules by offsetting the metalfrom slots 431-436, FIG. 23. Each receptacle module is then fixed inplace by means of a screw such as 437, FIG. 24, and a thread lockadhesive. While the support plate 420 is common to the six receptaclemodules 101-106, the multidock base 120 extends only over the area ofthe central four receptacle units so that connector means 311, 312, FIG.25, are accessible from behind modules 101 and 106.

Further screws 438 secure the connectors 311, 312 to the receptaclesupport plate 420.

Screws 439, FIG. 25, secure latch blocks 440, FIG. 27, and bracket 441to form the connectors such as 312. As seen in FIG. 26, latch blocks 440have notches 440a for securing mating connectors therewith.

For example, a cable may have a connector at one end engaged with aD-sub connector at position 450, FIG. 21, and a connector at theopposite end engaged with nine position D-sub connector part 451 or 452of connector 311 or 312, FIG. 25.

FIG. 27 illustrates how docking connectors 461-466 are fastened toprinted circuit boards 301, 302 by screws 467 and nuts 468 so as toclamp the spring contacts 470 to respective contact means 471-476, FIG.26, of the printed circuit boards. The sets of spring fingers 141-146,FIG. 10, formed by contacts 470 project through openings in the bottomof the receptacle modules 101-106 so as to engage external contacts ofhand-held data terminals inserted into the respective docking modulesthe same as explained in reference to FIGS. 1 through 6.

EXEMPLARY NETWORK CONFIGURATION, FIG. 28

A preferred network configuration would comprise a primary and multiplesecondary devices, where a controller module such as 200, FIGS. 21-26,is the primary device, and hand-held data terminals, printers andoptional interfaces and bridge products are the secondary devices.Hand-held data terminals also may operate in a network without acontroller. In a preferred configuration, communication in the networkis via a RS-485 bus. The controller 200 in addition to its datacommunication function may provide a power system for charging of theterminals in the docking modules such as 101-106, FIG. 23, and in somecases may also supply system power to the secondary devices. Where thecapacity of the controller 200 is exceeded, an auxiliary power unit(APU) may connect with one of the receptacles 450, FIG. 21 to receivecommunication from the controller 200, and may itself contain a powersystem for associated terminals for other secondary devices. The networkis thus preferably a local area network (LAN), with physicalconnectivity to the network provided by multidock units such as shown inFIGS. 7-11 and single dock units such as indicated in FIGS. 12-16. Thesedevices may be connected together using connection receptacles such asshown at 451, 452, FIG. 25, using simple twisted pair cabling. FIG. 28shows a block diagram of an exemplary network configuration, and a briefdescription of each network module is as follows:

Single Dock, (FIGS. 1-5, 12-16 and 28A)

The single dock is a passive device for electrical connection to acommunications network and power system. Charging voltage may beprovided through a LAN interface and a separate connector e.g. 76, FIG.5. The dock establishes proper alignment and retention for a hand-helddata terminal so as to enable host communications. A RS-232 port allowscommunication between a single dock as represented at 400, FIG. 28A, anda modem 401, or alternatively allows a direct connection between thesingle dock 400 and a host.

Multidock, (FIGS. 6-11 and 23-28)

A desired number of hand-held data terminals are connected to the localarea network with one or more multidocks as represented at 411 and 412,FIG. 28. Six single terminal modules are integrated into one enclosureas illustrated in FIG. 23. Quick release connectors such as 311, 312,FIG. 25, located at each end, allow connectivity to additional terminalinterfaces and other devices. Individual optional locking devices areavailable for providing security (preventing removal of a terminal fromits docking receptacle without a key or the like).

Auxiliary Power Unit, (FIGS. 28 and 29, 29A)

An auxiliary power unit such as represented at 421, FIG. 28, may developcharging voltage and operating power for up to twenty-four hand-helddata terminals, e.g. associated with four multidocks such as 422. In aparticular system a controller 400 may be capable of charging onlytwenty-four hand-held data terminals on its primary LAN channelindicated at 425. The auxiliary power unit 421 may be used on asecondary LAN channel 426 or used to extend beyond the originaltwenty-four terminals on the primary LAN channel 425. A repeaterreshapes the RS-485 signal so that it may drive an additionaltwenty-four logical units. Each functional block of the auxiliary powerunit 421 is shown in FIG. 29.

In FIG. 29, the secondary LAN channel may comprise conductors 426A and426B, while output channel 427 from the auxiliary power unit to themultidock 422, FIG. 28, may comprise conductors 427A and 427B. Theconnection between controller 400 and auxiliary power unit 421 mayadditionally include a direction control line 431, for controllingrepeater components 432 and 433. As represented in FIG. 29A, a plusfifteen volt power supply component 435 and a five volt regulatorcomponent 436 may also be included in the auxiliary power unit, and mayreceive a conventional commercial one hundred and twenty voltalternating current via a receptacle essentially corresponding toreceptacle 230, FIG. 18.

Controller, (400, FIG. 28)

The network controller 400 may be a multipurpose communicationscontroller designed to provide a flexible interface for communicationsbetween a customer's host computer and hand-held data terminals and thelike. Data ports may comprise a host port leading to a host channel 431,and one to three terminal ports such as associated with a channels 425,426 and 432 in FIG. 28. An optional LAN port may be selected throughsoftware which precludes the use of the third terminal port associatedwith channel 432 in FIG. 28. The second LAN port and secondary channel426 is connected in parallel with the primary LAN port associated withchannel 425, for added configuration capabilities.

Flexibility allows the controller 400 to be used as a communicationgateway at a host location or as a LAN interface device in remote depotswhere a multiplicity of hand-held data terminals are to be downloaded,have their batteries recharged and so on. Port expansion is possible bychaining additional controllers together via the communications ports.

The mechanical design allows the controller 400 to connect to multidockssuch as 411 with quick-connect cables for easy configuration andserviceability. The exemplary controller 200 of FIG. 21 may have sixconnectors leading to channels such as indicated at 425, 426, 431, 432and 433.

In the example of RS-485 LAN, all devices which interface to the LANconnect to a single wire pair using a balanced transceiver. Thisstandard is advantageous since it allows for multiple drivers andreceivers, high noise immunity over relatively long lines, operationwith wide common mode voltages, and the provision by the drivers of selfprotection against contention.

The RS-232 interface does not directly affect the architecture of thecontroller 400. Under normal system configurations, this interface willbe used to communicate with various modems and non-LAN products.

The controller 400 may be configured as a communications controller.Four sync/async RS-232 ports are software configured for host and remotecommunication channels. A RS-232 port will enable host communicationsusing the most common asynchronous and synchronous protocols. Theseinclude Bisync, two-way TTY and ADCCP. During system configuration, thetarget protocol is specific and soft-loaded from a removable diskinserted in the disk receptacle slot 224, FIG. 18, so as to be loaded inexecutable RAM.

The dimensions of the controller 200 are generally as follows:Height--9.5 inches max., width 13.0 inches max., depth--7.5 inches. Theweight is five pounds maximum. As previously described, the controllerwill have the option to be rigidly attached to a surface or wall. Themounting technique allows access to all cables and power connections,and removal of adjacent multidocks without removing the controller fromits mounting surface.

Connectors

The RS-485 LAN may comprise one primary part and one secondary port. Theports may use nine pine D-sub connectors. Signal definition isidentified below.

    ______________________________________                                        Pin Number      Signal Name                                                   ______________________________________                                        Primary Port (J6)                                                             1               V+                                                            2               +RS-485                                                       3               -RS-485                                                       4               V+                                                            5               Direction                                                     6               N.C.                                                          7               GND                                                           8               GND                                                           9               N.C.                                                          Secondary Port (J7)                                                           1               N.C.                                                          2               +RS-485                                                       3               -RS-485                                                       4               N.C.                                                          5               Direction                                                     6               N.C.                                                          7               GND                                                           8               GND                                                           9               N.C.                                                          ______________________________________                                    

Each of the RS-232 ports are fifteen pin D-sub male connectors, with pinassignments as follows:

    ______________________________________                                        Pin Number    Signal Name                                                     ______________________________________                                        1             N.C.                                                            2             -TXD                                                            3             DTR                                                             4             -RXD                                                            5             DSR                                                             6             RTS                                                             7             CTS                                                             8             GND                                                             9             N.C.                                                            10            N.C.                                                            11            TRXCO                                                           12            TRXCI                                                           13            RTXCO                                                           14            RTXCI                                                           15            N.C.                                                            ______________________________________                                    

The LCD display 221 may be a two line by sixteen character format. Thekeyboard may be a sixteen position four row by four column matrix.Depression of the keys may result in positive tactile feel.Environmentally the assembly may resist exposure to moisture.

The AC line cord my be removable from receptacle 230.

The disc drive associated with loading slot 224 may comprise a 3.5 inchhalf-height unit capable of an unformatted capacity of one megabyte perdisk (720 KB formatted). An optional two megabyte per disk drive isavailable.

Exemplary Controller Circuit, (FIG. 30)

A discussion of the functional blocks of the exemplary controllercircuit of FIG. 30 is presented in the following paragraphs.

Microcomputer 500, (FIG. 30)

The microcomputer 500 may be a type 80C186, some applicable featuresbeing as follows:

-- 16 bit external bus

-- Clock generator

-- Two independent DMA channels

-- Programmable interrupt controller

-- Three programmable 16-bit timers

-- Programmable memory and peripheral chip select logic

-- Programmable wait-state generator

-- Local bus controller

Additional detailed information is available in the Intel 80C186 user'smanual.

The microcontroller memory map of TABLE A on the following page givesthe general organization of various functions within the memory space byway of example.

                  TABLE A                                                         ______________________________________                                        Controller Memory Map                                                         ______________________________________                                        1 #STR1##                                                                     ______________________________________                                    

Since the application software may reside in RAM component 501 and inremovable disk storage, board level EPROM component 502 may only provideboot functions and diagnostics. This approach allows a stable welltested EPROM to be released with the system without future updates. Asocket is preferably provided for easy access.

All application programs execute from RAM (e.g. 501, FIG. 30A). Thismemory space is a maximum of 786 K (see memory map in TABLE A). Allapplication programs are retained on the removable 3.5 inch disks andare booted to RAM on power up. This allows RAM to be volatile,eliminating the need for optional battery back-up in some cases.

Two 85C30 SCC's, SCC1 and SCC2, FIG. 30B, may be used for host andterminal communications. The four channels may be configured assynchronous or asynchronous, RS-232 ports. One of the four communicationports may be software configured for RS-485 LAN communications.

Real-time clock component 550 may be a Motorola type MC146818. Thisdevice is power backed-up to maintain accurate time during powerinterruptions of various durations depending on the backup options. Whenan external battery is not used, a capacitor maintains memory and timefor up to two weeks. The battery option may extend clock operation formore than three months.

Along with internal registers for time, date and other data, theMC146818 provides fifty bytes of general purpose battery backed-up RAM.

SYNC/ASYNC interface component 560, FIG. 30B, may comprise ports A, B, Cand D as shown at the right in FIG. 30B. For synchronous protocols,transmit and receive clock lines are available. The controller orconnecting device may generate the clocks and is selected by a directionsignal from the microprocessor and use of one of two possible cablesbetween the host and controller.

Autoanswer modems may be connected to this port, and autodial may beinitiated using Hayes commands.

The LAN interface component 570, FIG. 30B, may consist of primary andsecondary channels. Each channel is driven by an RS-485 transceiver. Theprimary channel can drive twenty-four logical units or transceivers.Multidocks connect directly to the controller using the primary channelwith the use of cables. The secondary RS-485 channel connects toadditional multidocks using cables and an APU (FIGS. 29-29A) forcharging.

The RS-485 or the fourth RS-232 port is selectable through software(485SEL). This allows communication with four RS-232 devices (e.g. hostand three modems) and also devices directly connected to the RS-485 LAN.

A LCD interface 571 may be a self contained module with data lines,read/write strobe and two control lines for enabling the module (PCS4)and controlling power to the device.

Keyboard interface 572 may strobe the four columns of the 4×4 matrix anddetect corresponding key closures on one of the four rows. Keyboardactivity may be interrupt driven using INIT3. Debounce key rollover willbe handled in the firmware keyboard driver. Once the interrupt isdetected the key code may be read from the keyboard interface. The chipenable signal may be PCS5.

The 3.5 inch disk drive controller 573 may be an Intel type 82072 highintegration floppy disk controller with built-in analog data separator.This provides the interface requirements to the 3.5 inch disk drive ofnetwork controller 200.

Five DMA sources may be logically "ORed" to the two available DMArequest inputs of the DMA controller of microcomputer 500. The softwaremay keep track of the active device within each group "ORed" to thespecific DMA channel. A list of the DMA sources and their respectivegrouping is listed below.

SCC Port A (LAN)=DRQ0

Disk Controller=DRQ1

The interrupt source and type of interrupt to the processor 500 may beas listed below.

    ______________________________________                                        Source           Interrupt Type                                               ______________________________________                                        Manual Reset     NMI                                                          SCC Channels A,B,C,D                                                                           INIT0                                                        Disk Drive Controller                                                                          INIT1                                                        Keyboard         INIT3                                                        ______________________________________                                    

A DC/DC converter 581, FIG. 30B, may provide logic power. It may bedesigned to operate over a wide input voltage range of thirteen totwenty volts. The converter is board resident and allows the use of arelatively inexpensive single output power supply used also for chargevoltage to the multidocks on the primary channel.

A linear regulator 582 may be powered by the plus fifteen volt powersupply and provide plus twelve volts to the disk drive.

A back-up battery is indicated at 583 and may consist of a 3.6 volt,three-cell nicad battery pack with a 500 amp-hour capacity.

A self oscillating buzzer 584 may be enabled under microprocessorcontrol.

Charge voltage and input power to the controller board may be providedby a single output power supply. Output voltage may be in the range fromnot less than fifteen volts to not greater than twenty volts. The supplymay be capable of sourcing 7.0 amperes and may current limit before 8.0amperes.

Software Discussion

The Network Controller 400, FIG. 28, may provide high-speed LANcommunications for directly connected hand-held terminals via acommunications protocol known by the initials NPCP (Norand PortableCommunication Protocol).

The Network Controller may provide both synchronous and asynchronouscommunications support for devices which are remote to the host site.This support may include auto-dial and auto-answer capabilities.

The Network Controller may provide communications support for existingTTY and ADCCP devices of Norand Corporation.

The Network Controller may support an existing file transfer protocolfor hand-held computers of Norand Corporation which consists of a singleupload session followed by a single download session.

The Network Controller may provide a migration path to a file transferprotocol which may require multiple uploads and downloads.

The file transfer system implemented by the Network Controller mayprovide a migration path for full-duplex Network Controller to NetworkController communications.

A mechanism may be provided to chain Network Controllers, eitherdirectly or over switched lines. The chaining mechanism may be used toprovide additional RS-232 ports at a host site or to establish a sessionwith a controller at a remote site.

The Network Controller may provide the host with a method for initiatinga communications session with a specific terminal (not necessarily ahand-held data terminal).

The Network Controller may provide a method for "broadcasting" a file orfiles to multiple terminals.

The Network Controller may provide a method for storing user files onthe system.

The Network Controller may provide a method for downloading filesrequested by hand-held data terminals, independently of a host computer.

The Network Controller may provide a method for downloading files tohand-held data terminals under the direction of a host computer. Theorigination of the file may be transparent to the hand-held terminal.

Communication ports on the Network Controller may be softwareconfigurable.

The Network Controller may provide the user with an easy-to-useinterface for changing configuration parameters.

System Configuration

The Network Controller may be configured through a menu driven programusing the keyboard and display.

The following examples represent some possible system configurations.

(A) Host to local Network Controller configurations:

    ______________________________________                                        2 #STR2##                                                                     3 #STR3##                                                                     4 #STR4##                                                                     ______________________________________                                    

Network Controllers at the host site may be configured with four RS232ports, or with three RS232 ports and one RS485 port. The RS485 port isused if hand-held computers are in a LAN at the host site. One of theRS232 ports is used for communication with the host, and the remainingRS232 ports are used for remote communications. Currently, the host portdata-link protocol must be transparent point-to-point bisynchronous orasynchronous with (optional) parity checking. The host port may beconfigured at speeds up to 19,200 bps.

Local Network Controller to remote Network Controller configurations:

    ______________________________________                                        5 #STR5##                                                                     6 #STR6##                                                                     7 #STR7##                                                                     8 #STR8##                                                                     ______________________________________                                    

Several options are provided for support of remote sites. NetworkControllers at remote sites have one RS232 "host" port, forcommunications with a "host" Network Controller, and one LAN port. Thecommunications link to the host controller can be manually configured touse either ADCCP or a TTY extension as the data-link protocol. ADCCPports on a host controller may communicate with either remotecontrollers configured for ADCCP or with ADCCP terminals in Multi-quadLockboxes. TTY ports on a host controller may communicate with 4300/4400terminals, 101/121/141 terminals or other TTY devices of NorandCorporation. The host controller determines if a remote device is aNetwork Controller or an ADCCP/TTY device, when the connection is made.The host may dynamically configure RS232 ports on a Network Controlleras either ADCCP or TTY ports when the port is activated. Thisfacilitates the use of a single port for synchronous communications toremote Network Controllers and asynchronous communications to TTYdevices.

Information on 4300/4400 terminals which may operate on the network ofFIGS. 28, 39 and 40, for example, and other exemplary details are foundin the following pending applications:

(1) Cargin, Jr., Kelly, Fischer, Gibbs, Boatwright and Durbinapplication for patent entitled "HAND-HELD COMPUTER TERMINAL" U.S. Ser.No. 07/339,330 filed Apr. 14, 1989, Attorney Docket No. 6808.

(2) Miller, Koenck, Walter, Kubler, Cargin, Jr., Hanson, Davis andSchultz applications for patent entitled "DATA CAPTURE SYSTEM WITHCOMMUNICATING AND RECHARGING DOCKING APPARATUS, AND MODULAR PRINTER ANDHAND-HELD DATA TERMINAL MEANS COOPERABLE THEREWITH"

(2a) U.S. Ser. No. 07/346,771 filed May 2, 1989, Attorney Docket No.6649-Y, Express Mail Label No. LB 168 165 327.

(2b) U.S. Ser. No. 07/347,602 filed May 3, 1989, Attorney Docket No.6649XX, Express Mail Label No. NB 430 240 943

(3) Miller, Traeger, Kubler, Cargin, Jr., Hanson, Davis and Schultzapplications for patent entitled: "DATA COMMUNICATION SYSTEM WITHCOMMUNICATING AND RECHARGING DOCKING APPARATUS FOR HAND-HELD DATATERMINAL"

(3a) U.S. Ser. No. 07/347,298 filed May 2, 1989, Attorney Docket No.36504Y, Express Mail Label No. LB 168 165 305

(3b) U.S. Ser. No. 07/347,849 filed May 3, 1989, Attorney Docket No.6504XX, Express Mail Label No. NB 430 240 954

The entire disclosure of each of these pending applications includingthe drawings and Appendices is hereby incorporated herein by referencein its entirety.

Software Interface

The Network Controller maintains sessions between the host computer andhand-held computers of Norand Corporation (or other devices) on logicalchannels. As used here, "channel" consistently refers to a logical datachannel and "port" refers to the physical link, which may contain one ormore logical channels. Data from the Network Controller to the host isidentified by channel number and record type. With the possibleexception of an initialization record, data from the host is sent inresponse to a "channel request" from the Network Controller and isidentified by record type only. (Record types "0" to "5" are, for themost part, compatible with NI315/NI311 record types).

Logical Channels--Data transfers to/from the host computer are onlogical channels. The logical channel identifier field, which precedesdata to the host, consists of a 1-byte "controller channel" followed bya 1-byte "terminal channel". Controller channels may contain terminalchannels ranging from "1" to "9". Controller channels range from "0" to"9". New controller channels are opened each time a secondarycontroller--with multiple "terminal" ports--connects to the "host"controller. An identification record is sent to the host when a newcontroller channel is opened. The identification record contains alocation identifier for the new controller, port information, and achannel number for the controller.

Note: Only one controller channel is required, to the host, if nosecondary controllers have multiple terminal ports. Data transfers forsecondary controllers can occur on the primary controller channel (e.g:"0"). In this case, the host could treat the 2-byte channel identifieras a single field and avoid double indexing, or, optionally, the channelidentifier could be reduced to a 1-byte field.

Records from the Network Controller to the host computer.

Records from the Network Controller are always preceded by a channelidentifier, followed by a 1-byte record type. Network controller recordtypes are:

0--UPLOAD DATA--Upload data records contain "upload" data from hand-heldterminals. The host is guaranteed that the data from (or to) a terminalis contiguous on a logical channel.

1--END-OF-SESSION--End-of-session records are sent after each hand-heldsession completes, to indicate the status of the communications session.

2--DATA REQUEST--Data request records are used to request data from thehost computer. The host may respond with a data record, a file directiveor an end-of-data record.

3--INACTIVE STATUS--Active/Inactive status records are sent by thecontroller when the host port is inactive. An inactive status recordindicates that no terminals are currently active on the channel.

4--ACTIVE STATUS--Active/Inactive status records are sent by thecontroller when the host port is inactive. An active status recordindicates that a terminal(s) is currently active on the channel.

5--ACTIVATE REQUEST--Activate request records are used to obtain theinformation from the host which is necessary to activate the specifiedchannel. Activate requests are sent for a physical port whenever theport is disconnected and include the status of the previous activaterequest for the port. The host may respond with an auto-dial activationrecord, an auto-answer activation record, or with a deactivate record.Auto-answer activation records may include a "timeout period" specifiedin minutes. If the timeout period expires, the port will be deactivatedand a new activation request will be generated for the port. Thisfeature will allow a port to be toggled between auto-answer andauto-dial.

Note: Modem configuration information is only required for modem typesnot supported by Norand. Note: The activate request record replaces theNI311/NI315 phone request record.

6--SPECIAL REQUESTS--Special requests are used to prompt the host withan extended set of Network Controller requests. The host must examine a"subtype" filed to determine the type of special request. Currently, twosubtypes of special requests are required:

1--FILE REQUEST--File requests are sent to the host computer each time aNetwork Controller is brought-on-line. The host may respond to a filerequest with a one of several possible file directives or with anend-of-data record. File requests/directives can be used to load andmaintain files stored on the Network Controller diskette and in RAM. Thecontroller will send file requests to the host until the host respondswith an end-of-data record. The file request option may be turned on oroff with a flag in the initialization record.

2--CONNECTION REQUEST--Connection requests are sent to the host to allowthe host to establish a communications session with a specific device orterminal. The connection request includes a field to identify thelocation of the Network Controller which generated the request. The hostmay respond with a device identifier (terminal ID) to establish asession or may respond with an end-of-data record. The connectionrequest option is enabled with a flag in the initialization oractivation record. If the option is turned on, the host will be promptedwith a connection request: 1) at the beginning of a session with aNetwork Controller, 2) after each end-of-session record is sent, and 3)after a fixed time period expires with no activity on a channel. Anend-of-session always follows a connect request, either after therequest fails or after the terminal session completes.

Note: Inactive status records will not be sent to channels withconnection requests enabled.

7--DIRECTIVE STATUS--Directive status records are sent to the hostcomputer to supply the host with completion status information for anoutstanding host directive. The directive type is included in the statusrecord.

8--IDENTIFICATION RECORD--A Network Controller may be configured withthe keyboard to send a location identifier to the host computer or hostNetwork Controller. If the identification record is enabled it will bethe first record sent in a communications session. The identificationrecord is required for remote Network Controllers. The identificationrecord includes a location ID, port information, the number of non-host"terminal" ports on the controller. If this number is greater thanone: 1) another "controller channel" will be opened to the host, 2) theidentification record will be forwarded to the host on the new channel,3) an initialization record will be expected, from the host, on thechannel.

Records from the host to the Network Controller.

Records are sent from the host to the Network Controller in response tochannel requests from the controller, with the exception of the firstinitialization record. Host record types are:

0--DOWNLOAD DATA--Download data records are sent from the host to thecontroller in response to download requests, and connection requests.

1--END-OF-DATA--End-of-data records may be sent from the host to thecontroller in response to data requests and special requests. Theend-of-data record indicates that no data exists for the type of requestspecified.

2--INITIALIZATION RECORD--The initialization record is used to configurethe host/Network Controller communications session. The initializationrecord is sent at the beginning of a communications session with acontroller. For remote controllers, the initialization record is sent inresponse to an identification record.

3--AUTO-ANSWER ACTIVATION RECORD--Auto-answer activation records aresent in response to an activation request and may include optional modemand port configuration parameters. An auto-answer activation record mayalso include an optional timeout parameter, which contains the maximumnumber of minutes that the controller should wait for a connection onthe port. After the timeout has expired, the port will be deactivatedand another activation request will be sent to the host.

Note: The auto-answer activation record replaces the NI311/NI315"cancel-auto-dial" record.

4--AUTO-DIAL ACTIVATION RECORD--Auto-dial activation records are sent inresponse to an activation request and include a phone number and mayinclude optional modem and port configuration parameters.

Note: The host can use activation records to dynamically change porttype (e.g. ADCCP to TTY).

5--DEACTIVATE (for one minute)--Deactivate records may be sent by thehost computer to deactivate a channel requesting activation, for oneminute.

6--HOST DIRECTIVE--A host directive may be sent by the host in responseto a special (file or connect) request or data request from the NetworkController. The host directive contains a "subtype" field. The host willreceive a status after the directive has completed, either normally orabnormally. Currently, five subtypes of host directives are required:

1--FILE UPLOAD DIRECTIVE--An upload request can be used to upload a userfile stored on the disk of the controller which generated the filerequest. For example, this feature can be used to obtain the directoryof user files on the controller disk. After the requested file isuploaded the controller will sent another file request to the host.

2--LOAD DIRECTIVE--A load directive may be sent in response to a filerequest, to download a file to the controller which generated the filerequest. The load directive must include a directory entry whichspecifies the file name, date, size, etc. After the load directive hasbeen sent, the controller will send data requests for file data untilthe host responds with an end-of-data record. The data will be writtento a file on disk, with the name specified. Existing files with the samename will be overwritten and excess space will be recovered. After thefile has been successfully written, a status field will be set toindicate that the file is in a defined state and is available for use.

3--DELETE DIRECTIVE--A delete directive may be sent in response to afile request to delete a data file on the Network Controller. A deletedirective will fail if the file is in use.

4--DOWNLOAD DIRECTIVE--A download directive may be sent in response to adata request and is used to download a file which exists on acontroller's disk to a terminal on the attached LAN. The terminal whichreceives the download data should not be able to distinguish between"download directive data" and data from the host.

5--CONNECT DIRECTIVE--A connect directive may be sent in response to a"connect request" from the Network Controller to enable the host toconnect to a specific terminal on the LAN. The connect directive mustcontain a terminal identifier.

Remote Network Controller Interface

"Remote controllers" can be configured for connection to a "hostcontroller", through any of the four ports, over either a switched ornon-switched line. The connection will be synchronous and will use ADCCPfor data-link control. The controller will acknowledge an ADCCP poll(SNRM) directed to its destination address. The remote controller willthen send an identification record which will include the logicallocation of the controller (for customer use) and a control byte with adevice identifier.

Remote Network Controller record types are identical to the record typesfor a local Network Controller. If the remote controller is configuredfor multiple terminal ports, the host controller will open a new channelfor the remote controller and will simply pass all data through, to thecustomer's host computer. If the remote controller is configured for asingle LAN port, the host controller can, optionally, interceptidentification and activation records, and can pass data through onexisting channels to the host.

Remote controllers will default to auto-answer mode.

Auto-dialing with a remote controller:

Controllers in a remote "depot" can be configured to auto-dial a phonenumber(s) at the host site. A primary and alternate phone number may beentered with the keyboard, along with an associated dial time, number ofretries, retry wait time, failure threshold, modem type, and minimumnumber of terminals. The primary phone number will first be dialed afterthe dial time is reached and the minimum number of terminals areconnected. The minimum number of terminals will default to one, and mustbe non-zero. If the dial time is zero, the primary number will be dialedas soon as the minimum number of terminals are connected. The controllerwill retry the primary number after the wait time has expired and atleast one terminal is connected. Retries will continue until the retrycount is exceeded or the failure threshold is reached. If the failurethreshold is reached the alternate phone number will be used for thenext call.

Remote controllers will default to auto-answer mode.

ESTABLISHING COMMUNICATIONS SESSIONS WITH TERMINALS OF NORANDCORPORATION

A. NON-LAN TERMINALS. This category of terminals includes existing TTYand ADCCP terminals of Norand Corporation, and 4330/4400 terminals on anRS232 interface. Non-LAN terminals may respond to a poll from the host(or host controller) with one or more upload data blocks, and thenreceive zero or more download blocks from the host. The host, typically,identifies the terminal by an identifier in the upload data andassociates download data with the identifier.

Note: Support for booting 3X/4X terminals in a non-LAN environment iscurrently undefined.

B. LAN TERMINALS. LAN terminals are attached to a high-speed RS485multi-drop link on the Network Controller. The Network Controllerdetermines what logical terminals are attached to the network, and isresponsible for maintaining a current terminal table. The terminal tablemust include a LAN address and an associated terminal name, which doesnot need to be unique and can be a "wild card" name. The name of aterminal can be fixed or can be set by a customer. For example, theterminal name can be a function of a bakery route ID, or can behard-coded in the firmware of the device supporting the terminal.

1. HOST-TO-TERMINAL SESSIONS. Host-to-terminal sessions can be initiatedin one of two ways:

a) LISTEN-ANY (MYID, YOURID)--In this mode a controller applicationidentifies itself and will listen to any terminal trying to connect to"myid". After a successful connection, a terminal name is returned in"yourid". "Myid" could be hard-coded in the software/firmware of thecontroller and terminal.

b) OPEN-SPECIFIC (MYID, YOURID)--In this mode a controller applicationwill attempt to connect to a terminal specified by "yourid".Open-specific requests are generated when the host responds to aconnect-request with a terminal ID. The host and terminal must agree onthe terminal ID (e.g. "yourid") used to make the connection.

After a terminal connects, the controller simply provides a link betweenthe host and the terminal. In a single session, the terminal can sendzero or more upload records to the host, and then the host may send zeroor more download records to the terminal. Nothing prevents a terminal onthe LAN from having additional uploads and downloads or fromestablishing multiple sessions.

2. CONTROLLER-TO-TERMINAL SESSIONS--The Network Controller will providea continuous application which will attempt to communicate to devices onthe LAN, whether or not the host is connected. The application will beprovided for the purpose of downloading data files from the system diskto terminals on the LAN. This facility could be used to load HHC's withoperating system files or a kernel program, for example. The applicationwill issue a listen-any (myid, yourid) and will establish sessions withterminals attempting to connect to "myid". The terminal can optionallysend a list of the names of files to download. If the terminal does notsend a list of download files, the controller application will scan adata file directory for "boot" files and will download those files tothe terminal. The host computer will be provided with facilities tomaintain data files kept on the controller. In addition, a facility willbe provided through the controller keyboard and display which allows theuser to load data files from a 31/2 inch MS-DOS diskette. The host willreceive no status information for controller-to-terminal sessions. Usingthis option while the host is in session may result in contention for afile.

STORE-AND-FORWARD FILE TRANSFER SUPPORT

The Network Controller will provide the host computer with thefacilities to maintain data files on the Network Controller. (Refer tothe section describing file requests and host directives.) In addition,a facility will be provided to allow the user to load data files from a31/2 inch diskette. All data files will be written to the NetworkController system diskette, and will be read into RAM during thecontroller's boot cycle. An entry for each data file will exist in adata directory file. The fields in the directory entries are primarilyunder host control and are intended for version control. The directoryentry will include a type field, which may be used to connect the fileto a specific application (i.e. a boot application). Data files which donot have an entry in the directory file will be deleted during the bootcycle.

Host file maintenance will occur after the host session has beenestablished, and before communications begin on any of the other NetworkController ports. The host is responsible for examining the data filedirectory, via a "directory file request", and ensuring that all datafiles are current. After normal communications begin, the host maydirect that any data file be sent to a terminal requesting a download,by sending a download directive which contains directory information forthe file.

A task will run continuously on the Network Controller and will open twotypes of NPCP "listen" sessions. The first type will simply send "boottype" files to LAN terminals which connect to it. The second sessionwill read a list of files from terminals which connect to it and thenattempt to download those files to the terminal. The user is responsiblefor ensuring that any necessary files are in a defined state on theNetwork Controller.

EXAMPLE TELECOM SESSION--The following example is a step-by-steprepresentation of a host to Network Controller communications session.It is important to remember that any logical sequence of steps willproceed in a "single-file" order on a logical channel, but that stepsfrom different logical channels can be interspersed on the host port.

1. The host opens the communications port to the Network Controller.

2. The Network Controller sends an (optional) identification record tothe host.

3. The host sends an initialization record to the Network Controller.The initialization record configures the controller and enables filerequests.

4. The controller sends a file request to the host.

5. The host responds by sending an upload directive to the controller toupload the directory file.

6. The controller sends a directory of the data files on disk to thehost, followed by the directive status.

7. The controller sends another file request to the host.

8. The host responds by sending a file "load" directive to thecontroller.

9. The controller determines that the load directive is acceptable,opens the respective file, and sends a data request to the host.

10. The host sends a data record to the controller.

11. The controller sends a data request to the host.

12. Steps 10 and 11 may be repeated any number of times.

13. The host sends an end-of-data record to the controller.

14. The controller closes the file, updates the status of the file inthe file directory, and sends a directive status to the host.

15. The controller sends another file request to the host.

16. The host sends an end-of-data record to the controller.

17. The controller sends an activation request for the LAN port and eachof the remote ports (ports 2 and 3).

18. The host responds with an auto-answer activation record for the LANport and port 2, and an auto-dial activation record for port 3. Port 2is configured to be asynchronous and port 3 is configured to besynchronous. Connection requests are enabled for the LAN port.

20. A connection is established with a remote controller on port 3.

21. The remote controller sends an identification record to the host(via the local controller).

22. The host sends an initialization record to the remote controller,which enables file request processing.

23. The remote controller sends a file request record to the host, andfile request processing proceeds as with the local controller.

24. The remote controller sends an activation request, for its LAN port,to the host.

25. The host responds by sending an auto-answer activation record to theremote controller.

26. The remote controller sends an upload data record, from a terminalon its LAN port, to the host.

27. Step 26 can be repeated any number of times.

28. The remote controller sends a download data request to the host.

29. The host responds with an end-of-data record.

30. The remote controller sends a session status record from theterminal to the host.

31. Activity switches to the local LAN, and the local Network Controllersends a connect request record to the host.

32. The host responds with a connect directive to establish a sessionwith a specific terminal.

33. The terminal is located and a directive status is sent to host whichindicates that a session is established.

34. The local controller sends an upload data record, from the terminalto the host.

35. Step 34 can be repeated any number of times.

36. The local controller sends a data request record to the host.

37. The host responds by sending a "download file directive" to thecontroller.

38. The controller opens the specified file, and downloads the entirefile from the controller (RAM) disk to the terminal active on the LANchannel.

39. The controller sends a "directive status" record to the host toindicate that the file was downloaded successfully.

40. The controller sends the next data request record, for the channel,to the host.

41. The host responds by sending a download data record.

42. Steps 40 and 41 or steps 40, 37, 38 and 39 may be repeated anynumber of times, until the host sends an end-of-data record.

43. The host sends an end-of-data record for the channel.

44. The controller sends an end-of-session record, from the terminalactive on the channel, to the host.

45. The controller sends another connection request to the host.

46. The host responds by sending an end-of-data record to thecontroller.

47. The controller randomly establishes a session with another terminalon the LAN.

48. A communications session proceeds on the channel as in steps 34through 44.

49. The controller determines that no terminals are available on theremote auto-dial port (port 3), deactivates the port and sends anactivation request record, for the port, to the host. The activationrequest contains a status field which indicates why the port wasdeactivated.

50. The host responds by sending an auto-answer activation record to thecontroller, which re-configures port 3 as an auto-answer, asynchronousport. The port is now capable of answering calls from single 4300/4400terminals (not in a LAN) and existing TTY devices.

51. The controller receives an upload data record from a 4300/4400terminal on port 2.

52. The controller transfers the data to a host channel and sends thedata on to the host.

53. Steps 51 and 52 may be repeated any number of times until the4300/4400 has finished uploading data.

54. The controller sends a download data request, for the 4300/4400terminal, to the host.

55. The host responds by sending a data record.

56. Steps 55 and 56 may be repeated 0 or more times.

57. The host sends an end-of-data record for the 4300/4400 terminal.

58. The controller sends the end-of-session record from the terminal tothe host.

* Once set, activation parameters remain in effect until they arespecifically reset. Default activation parameters are contained in aconfiguration file on the controller's disk.

** Enabling connection requests will probably be the exception, ratherthan the norm. If connection requests are not enabled, connectionrequests will not be generated and terminal sessions will be establishedin a way similar to that used in Norand's existing protocol converters(e.g. The controller will accept upload data from any terminal, and passthe data on to the host. The host will use information in the uploaddata to associate download data with the terminal).

Description of FIG. 31

FIG. 31 illustrates exemplary logic for component 600, FIG. 30A. InputsPCS0 and PCS1 are identified at 601 and 602 in FIG. 31, andcorresponding inputs are apparent in FIG. 30A, which emanate from bus604. Input DCDRQ designated 606 in FIG. 31 will be seen to originate atthe disk drive controller 573, FIG. 30A. Inputs 611, 612 and 613 of FIG.31, designated DRQB, DBQC, DBQD, are apparent at the right of component600, FIG. 30A. Output signal lines 615 and 616, FIG. 31, are shown to beconnected to the microcomputer 500, FIG. 30A. Outputs 621 and 622, FIG.31, are seen in FIGS. 30A and 30B to be associated with bus 624 and tolead to the respective serial communications controllers SCC1 and SCC2,FIG. 30B. Input 626, FIG. 31, is seen in FIGS. 30B and 30A to originateat serial controller SCC1.

Description of FIGS. 32A and 32B

FIGS. 32A and 32B show a preferred implementation of the auxiliary powerunit (APU) shown at 421 in FIG. 28, and an earlier implementation beingshown in FIG. 29. In accordance with the present invention, theauxiliary power unit of FIGS. 32A and 32B enables the expansion of theLAN system beyond the initial twenty-four docking units. The deviceprovides power for an additional twenty-four hand-held computerterminals, so that the batteries may be recharged during thecommunication process. The APU circuitry of FIGS. 32A and 32B alsoprovides for a bi-directional repeater for the RS-485 communicationsignals. A commercially available LAN configuration can be expanded to amaximum of seventy-two docking units utilizing one network controller400, FIG. 28, twelve multi-dock systems such as illustrated in FIGS.23-27 and two auxiliary power units as represented in FIGS. 32A, 32B.

The connector arrangement as shown at 450, FIG. 21, on the back panel ofthe network controller and corresponding connectors at the back of theAPU unit 421, FIG. 28, simplify the configuration of systems and allowflexibility in routing of external interconnecting cables.

The APU circuitry of FIGS. 32A and 32B is unique because the repeatercircuit is bi-directional and does not require an external signal todetermine the direction of data (such as provided by direction controlline 431, FIG. 29). An energy detection circuit comprised of components32-U6A and 32-U6B, FIG. 32B, automatically determines which side of therepeater circuitry of FIG. 32A is receiving the data, and enables therepeater circuit for that direction. The enable control lines areindicated at 633, 634, FIGS. 32A, 32B. At that time, the repeatercircuit for the opposite direction is disabled. Once data activitystops, both repeater circuits are disabled. The energy detect circuit ofFIG. 32B then monitors both sides of the APU repeater circuit for dataactivity and reactivates one or the other of the two repeaters asrequired.

By way of example, the respective components of FIGS. 32A and 32B may beof the following types:

    ______________________________________                                        32-U6A, 32-U6B, FIG. 32B                                                                            Multivibrator                                                                 e.g. 74HC123                                            32-U2, FIG. 32A       Bus Repeater                                                                  e.g. Type 75178B                                        32-U3, 32-U4, 32-U5, FIG. 32A                                                                       Bus Repeater                                                                  e.g. Type 75177B                                        32-REG1, FIG. 32B     Regulator                                                                     e.g. LM317T                                             ______________________________________                                    

Description of FIG. 33

FIG. 33 illustrates the circuitry for the RS232 interface components 560for ports B, C and D of FIG. 30B. FIG. 33 specifically shows theinterface for port D wherein the signal CLKSELD shown at input 650 atthe left in FIG. 33 originates from a latch 651, FIG. 30A, and istransmitted via bus 652, FIGS. 30A and 30B. Component 654, FIG. 33, maybe a driver/receiver, for example MAX 235.

Description of FIGS. 34A, 34B and 34C

In FIGS. 34B and 34C, the RS232 interface component for port A, FIG.30B, is indicated at 660 and corresponds with the other interfacecomponents such as 654, FIG. 33. Thus, bus 652, FIGS. 30A and 30B,supplies the signal CLKSELA at input 662, FIG. 34A. Port selectcomponent 664, FIG. 30B, may be implemented as shown at 666 and 667 inFIG. 34A, these components being quad multiplexors, e.g. type 74HC157.The 485SEL signal for input 670, FIG. 34A, originates at latch 651, FIG.30A, and is transmitted by bus 652. The RS485 interface component 570,FIG. 30B, may be implemented as indicated at 675, FIG. 34B, andcomponent 675 may be a differential bus transceiver, e.g. type 96176.

Description of FIGS. 35A and 35B

FIGS. 35A and 35B illustrate an exemplary implementation of the powersupply components 581 and 582, FIG. 30B. The input at line 680, FIG.35A, may be between 13 volts DC and 20 volts DC and the output 681, FIG.35A, may supply plus twelve volts to the disk drive component, whileoutput 682 may supply plus five volts.

By way of example, component 690, FIG. 35B, may be a plus modulator,e.g. type UC494AC.

By way of example, the plus twelve volt output at 681 may be supplied bya regulator component 692, e.g. a voltage regulator type UA7812UC.

Description of FIGS. 36A, 36B and 36C

By way of example RAM controller 700, FIG. 30A, may be implemented asshown at 701, 702, FIG. 36B. Coupling of these components to address bus710 is indicated in FIG. 36A.

FIG. 36C shows a regulator 36-REG1, e.g. type LM317LZ, which is coupledvia line 712, FIGS. 36C, 36B, with a plus three volt regulator 36-REG2,e.g. type 581230. The input to components 701, 702 such as VBB1, VBB2and plus five volts (+5 V) have suitable banks of capacitors associatedtherewith and the same is true of other voltage inputs throughout thepreferred embodiment of a network controller. The showing of thesecapacitor banks has been omitted since this is a matter of routine forthose skilled in the art.

FIG. 36C also shows a RAM chip select signal at 714 (RAMCS). Otherconnections between FIGS. 36C and 36B are indicated at 716 and 718.

Description of Exemplary Microprocessor And Related Circuits (FIGS.37A-36F)

In FIG. 37A, the address bus 710 on a complete sheet of engineeringdrawings would be shown as leading to the sixteen bit inputs (A1-A16) oftwo EPROM chips (each 64KX8, e.g. 27C512). Such circuitry forimplementing component 800, FIG. 30A, is a matter of routine for oneskilled in the art, and need not be further described. The data from theEPROM 800 (e.g. D0-D7) is supplied to bus 801 (e.g. as signals DB0-DB7and AD8-AD15).

The RAM component 810, FIG. 30A, may be implemented as twenty-four CMOSSRAM chips, 32Kx8, e.g. PD43256C. Address bus 710 would supply inputs(e.g. A1-A15), while components 701, 702, FIG. 36B would providerespective select signals (e.g. RCE0, RCE23). A further description ofan implementation of component 810 is unnecessary since such circuitryis well within the routine skill of the art.

In FIG. 37A, the control and data bus 820 is shown which is associatedwith outputs (AD8-AD15) of the EPROM chips implementing component 820.For convenience of compact illustration of the circuitry, this bus 820is shown offset to the right in FIG. 37D. FIG. 37D also shows a bus part820A offset to the right from the corresponding bus part 820A of FIG.37. Otherwise, vertical lines of FIG. 37D are in alignment with thecorresponding vertical lines (i.e. 831, 832) in FIG. 37A.

Horizontal lines 841-852 in FIGS. 37A and 37B are in horizontalalignment and have been numbered for convenience of correlation of thesefigures.

In an actual engineering drawing, a vertical bus segment 820B is shownby the same vertical lines. Thus segments 820C in FIGS. 37C and 37B areidentical segments (rather than being connected between the figures).This same procedure has been followed with respect to bus segments 820D,820E in FIGS. 37E and 37F. Thus, in an actual engineering drawing thelines of bus segment 820B, FIGS. 37B and 37C, would be in directalignment with and would connect with the two lines of bus segment 820D,FIGS. 37E and 37F, and bus segment 820E of FIG. 37F would besuperimposed on and part of bus segment 820E of FIG. 37E. Horizontalline 861 has been numbered in FIGS. 37B and 37C to assist in correlatingthese figures. Horizontal line 862 has been numbered in FIGS. 37A and37E, and the horizontal bus segments 870 have been designated at thebottom of FIG. 37A and near the top of FIG. 37E. Bus segment 880 hasbeen labeled as a vertical segment in FIG. 37B and as a horizontalsegment in FIG. 37E, these segments being in alignment in the presentpatent drawings. Vertical bus segments 820G have been designated inFIGS. 37B and 37E since these segments are in vertical alignment in thepatent drawings. Horizontal lines 881 through 886 have been designatedin FIGS. 37E and 37F to assist in associating these figures.

Exemplary components for the circuitry of FIGS. 37A through 37F is asfollows:

    ______________________________________                                        37-U42, FIG. 37A     Buffer,                                                                       e.g. 74HC241                                             37-U28, FIG. 37A     D-Type Positive-                                                              Edge-Triggered                                                                Flip-Flop                                                37-U5, FIG. 37B      Microprocessor,                                                               e.g. Type 80C186                                         37-U6, 37-U7, 37-U8, FIG. 37C                                                                      Octal Latch,                                                                  e.g. 75HC573                                             37-U30               JK Flip-Flip,                                                                 e.g. Type 74HC112                                        37-U38, FIG. 37E     CMOS Clock,                                                                   e.g. Type MC146818P                                      37-U26               Programmable Logic                                                            "LANPAL"                                                                      (Type PALC22V10H)                                        37-U32, 37-U27       Bus Transceiver,                                                              e.g. 74HC245                                             ______________________________________                                    

Description of FIGS. 38A-38E

In order to assist in correlation of FIGS. 30A, 30B with the exemplaryimplementation of FIGS. 38A-38E, the communications bus has beendesignated 624 in the detailed implementation.

FIG. 38A shows components 901 and 902 for implementing serialcommunications controller chips SCC1 and SCC2. The address bus has beendesignated 710 in FIGS. 30A, 30B and FIGS. 38A, 38B and 38E. Data bus607, FIGS. 38A and 30B, has been designated with the same referencenumeral in FIGS. 38A, 38B and 38E.

The vertical line between FIGS. 38A and 38C has been designated 905, andthe horizontal lines between FIGS. 38C and 38D have been designated911-920. The horizontal lines between FIGS. 38D and 38E have beendesignated 921-928.

Component 930, FIG. 38B, may represent an implementation of the keyboardinterface 572, FIG. 30A. Component 940, FIG. 38E, may represent adetailed circuit for disk drive controller 573.

Exemplary type numbers for the major components in FIGS. 38A, 38B and38E are as follows:

    ______________________________________                                        Components 901, 902, FIG. 38A                                                                      Serial Communica-                                                             tions Controller,                                                             e.g. Type 85C30                                          38-U24, FIG. 38B     Octal Latch,                                                                  e.g. Type 74HC573                                        930, FIG. 38B        CMOS Keyboard                                                                 Encoder                                                                       e.g. Type 74C923                                         940, FIG. 38E        Controller,                                                                   e.g. Type 82072                                          ______________________________________                                    

Description of FIG. 39

FIG. 39 illustrates components corresponding to those of FIG. 29 butdiscloses the conception of utilizing energy detect circuits 951 and 952for eliminating the need for the direction control line 431, FIG. 29. Anexemplary detailed implementation of the teachings of FIG. 39 has beenshown in FIGS. 32A and 32B, and reference is made to the section headed"Description of FIGS. 32A and 32B" for further discussion of thisdevelopment.

Description of FIG. 40

FIG. 40 is an extension of the system of FIG. 28, and illustrates howthe system may be progressively expanded with the use of auxiliary powerunits such as 961 and 962, for example to include one or more furthermultidock units such as those indicated at 971-974 and 981-984.

This will serve to illustrate the manner in which the auxiliary powerunits of FIGS. 29, 32A, 32B and 39 may be utilized to chain furthermultidock units beyond the power supply capacity of the LAN controller400. In this example an auxiliary power unit such as 961 is connected toa connector such as indicated at 312 in FIG. 25 (where connector 311 iscloser in the chain to the primary LAN channel 425 of LAN controller400). Similarly, an auxiliary power unit might be added as indicated indash outline at 985 after multidock 974 in the primary chain, whereuponfour more multidock arrangements such as that of FIGS. 6, 7, 8, 10, 11and 23-27 could be added as needed. As indicated in FIG. 40, with theaddition of an auxiliary power unit 962 in the secondary channel 426, upto four multidock units for example, may be added in a secondary chain.

Description of FIG. 41

For the sake of a specific example, FIG. 41 indicates schematically theconductor paths which may be carried by each of the multidock printedcircuit boards such as printed circuit boards 301 and 302 in FIGS. 25and 26. For the example of three docking receptacles per printed circuitboard, each printed circuit board such as 990, FIG. 41, may have threedocking receptacle coupling locations 991, 992, 993. For the case of aprinted circuit board of a multidock, (e.g. 301, FIG. 25), which isclosest to the LAN controller 400, FIGS. 28 and 40, its end connector(e.g. 311, FIG. 25) would be connected to the LAN input terminals 994 ofa printed circuit board such as 990, and its connector terminals 995would receive one end of a flex cable such as 303, FIG. 25. Where theprinted circuit board was to be located in a multidock more remote fromthe LAN controller 400, (e.g. printed circuit board 302, FIG. 25), theother set of terminals 996 would receive the end of a flex cable such as303, FIG. 25, and the LAN output terminals 997 would be connected to thepin positions of an adjacent end connector, (e.g. connector 312, FIG.25).

The LAN input and output terminals 994 and 997 may be designated asfollows:

    ______________________________________                                               Terminal                                                                             Designation                                                            Number(s)                                                                            (FIG. 41)                                                       ______________________________________                                               1      CHG                                                                    2      +485                                                                   3      -485                                                                   4      CHG                                                                    5      DIR                                                                     6-11  GND                                                                    12-15  CHG                                                                    16     SPARE                                                           ______________________________________                                    

The terminals 995 and 996 would then have the following designations inFIG. 41:

    ______________________________________                                               Terminal                                                                      Number(s)                                                                            Designation                                                     ______________________________________                                               1-4    CHG                                                                    5-8    GND                                                                     9     +485                                                                   10     -485                                                                   11     DIR                                                                    12     SPARE                                                           ______________________________________                                    

By way of example, the following tables will explain theinterconnections of FIG. 40, having reference to the LAN controllerexample of FIGS. 34A, 34B, 34C, the auxiliary power unit of FIGS. 32A,32B, and the multidock printed circuit board terminal designation ofFIG. 41.

Table A shows the connections between controller 400, FIG. 40, andmultidock 411, for example.

Table B shows the connections between multidock 987, FIG. 40, andauxiliary power unit 961, for example.

Table C shows the connections between auxiliary power unit 961, FIG. 40,and multidock 971.

Table D shows the connections between the secondary channel of LANcontroller 400, FIG. 40, and the auxiliary power unit 962.

                  TABLE A                                                         ______________________________________                                        Connections Between                                                           400 and 411, FIG. 40                                                                      LAN                                                                           CONTROLLER   MULTI-                                                           Primary Channel                                                                            DOCK LAN                                                         Output (FIG. 34C)                                                                          INPUT                                                Terminal    Designation  Designation                                          Number      (FIG. 34C)   (FIG. 41)                                            ______________________________________                                        1           +15 V        CHG                                                  2           +465         +485                                                 3           -485         -485                                                 4           +15 V        CHG                                                  5           DIR          DIR                                                  6           --           --                                                   7           GND          GND                                                  8           GND          GND                                                  9           --           --                                                   ______________________________________                                    

                  TABLE B                                                         ______________________________________                                        Connections Between                                                           987 and 961, FIG. 40                                                                     MULTIDOCK LAN                                                                              AUXILIARY                                                        OUTPUT       POWER UNIT                                                       (FIG. 41)    LAN INPUT                                             Terminal   Designation  Designation                                           Number     (FIG. 41)    (FIG. 32A)                                            ______________________________________                                        1          CHG          N.U. (Not Used)                                       2          +485         +485                                                  3          -485         -485                                                  4          CHG          N.U.                                                  5          DIR          N.U.                                                  6          --           N.U.                                                  7          GND          GND                                                   8          GND          GND                                                   9          --           N.U.                                                  ______________________________________                                    

                  TABLE C                                                         ______________________________________                                        Connections Between                                                           961 and 971, FIG. 40                                                                       AUXILIARY  MULTI-                                                             POWER UNIT DOCK LAN                                                           LAN OUTPUT INPUT                                                 Terminal     Designation                                                                              Designation                                           Number       (FIG. 32A) (FIG. 41)                                             ______________________________________                                        1            +15 V      CHG                                                   2            +485B      +485                                                  3            -485B      -485                                                  4            +15 V      CHG                                                   5            N.U.       DIR                                                   6            N.U.       --                                                    7            GND        GND                                                   8            GND        GND                                                   9            N.U.       --                                                    ______________________________________                                    

                  TABLE D                                                         ______________________________________                                        Connections Between                                                           400 and 962, FIG. 40                                                                     LAN          AUXILIARY                                                        CONTROLLER   POWER UNIT                                                       Secondary Channel                                                                          Secondary (J3)                                                   Output (FIG. 34C)                                                                          Channel Input                                         Terminal   Designation  Designation                                           Number     (FIG. 34C)   (FIG. 32A)                                            ______________________________________                                        1          --           N.U.                                                  2          +485         +485                                                  3          -485         -485                                                  4          --           N.U.                                                  5          DIR          N.U.                                                  6          --           N.U.                                                  7          GND          GND                                                   8          GND          GND                                                   9          --           N.U.                                                  ______________________________________                                    

Of course, with the auxiliary power units of FIGS. 32A, 32B and 39, theconductors on the printed circuit board 990 labeled "DIR" would beunused, and could be omitted.

A unique feature resides in the construction of multiple ports of alocal area network as shown in FIGS. 25, 26 and 41, whereby ports 991,992, 993, for example, are coupled to rigid conductive signal pathwayssuch as "+485", "-485" in FIG. 41 formed directly on rigid printedcircuit boards such as 302, 302, FIGS. 25 and 26. Such rigid pathwaysmay be associated with LAN inputs such as 994 or 996 and LAN outputssuch as 995 or 997, and extend continuously therebetween.

Instead of separate rigid printed circuit boards 301 and 302 constructedas shown in FIG. 41, a single rigid printed circuit board may be usedper multidock, in which case, there might be six coupling locations suchas 991, 992, 993, per unitary printed circuit board, and the terminalssuch as 995 and 996 and any associated extra pathways could be omitted.

In FIGS. 25, 26 and 41, rigid power pathways "CHG" and "GND" traverseeach printed circuit board from end to end e.g. for the case of twoboards per multidock, from 994 to 995, or from 996 to 997, and e.g. forthe case of a single unitary rigid printed circuit board per multidock,from LAN input 994 to LAN output 997.

Summary With Respect to FIGS. 31-41

With the foregoing description, and the detailed circuitry shown inFIGS. 31 through 38E, a preferred embodiment of the circuitry forimplementing FIGS. 28, 30A, 30B, 39 and 40 will readily be understood bythose skilled in the art. Of prime importance is the preferredimplementation for the auxiliary power unit as described with referenceto FIG. 39, the flexibility of expansion of the docking capacity asshown in FIG. 40, and the LAN multiport arrangement of FIG. 41.

Description of FIGS. 42 and 43

FIG. 42 is a plan view of the solder side of a printed circuit boardsuch as 301 or 302 and thus corresponds with FIG. 26 except thatconductive paths are physically shown. FIG. 43 shows the opposite sideof the printed circuit board from FIG. 42, and the electricalconnections shown conceptually in FIG. 41, are shown as physicalconductive paths in FIGS. 42 and 43. In order to assist in correlatingFIGS. 42 and 43 with FIG. 41, reference numerals 990 through 993, 995and 996 from FIG. 41 have been applied in FIGS. 42 and 43.

The connectors such as 311 and 312, FIGS. 25 and 26, are coupled to theconductive paths on the printed circuit board via hole patterns 1021 and1022, FIGS. 42 and 43. In an actual embodiment, each socket of connector311 is connected with a respective hole of a pattern such as pattern1021 by a wire which extends axially of the socket at one end and curvesthrough ninety degrees so that its opposite end extends axially througha hole of the pattern and is soldered in place. Thus hole pattern 1021represents potential LAN input terminal positions to be coupled with aninput connector such as 311, and hole pattern 1022 may serve as LANoutput terminal positions to be coupled with an output connector such as312, FIG. 25. The corresponding hole patterns in FIG. 26 have beendesignated 1021A, 1021B and 1022A, 1022B to assist in correlating thefigures.

The network conductive data paths between terminals of the endconnectors 996 and 995 may be traced as follows:

network terminal 996-1, FIG. 43, copper strip sections 1031, 1032, FIG.43, through hole 1033, FIGS. 42 and 43, copper strip 1034, FIG. 42,through hole 1035, copper strip 1036, network terminal 995-1: and

network terminal 996-2, FIG. 43, copper strip 1041, through hole 1042,copper strip 1043, FIG. 42, through hole 1044, copper strip 1045, FIG.43, and network terminal 995-2.

The various branch data paths to contact sets 991-993 may be traced asfollows:

from network terminal 996-1 and network data path segment 1034, FIG. 42:

branch path 1051, FIG. 42, and contact 991-1;

branch path 1052, FIG. 42, and contact 992-1: and

branch path 1053, FIG. 42, and contact 993-1.

From network terminal 996-2 and network data path segment 1043:

direct engagement with contact 991-2, FIG. 42

From network terminal 996-2 and network path segment 1045, FIG. 43:

through hole 1061, branch path 1062, and contact 992-2

through hole 1063, branch path 1064, and contact 993-2

The branch data paths to the hole patterns 1021 and 1022 are as follows:

From network data terminal 996-1 and network data path segment 1031,FIG. 43:

branch data path 1071, FIG. 43, to hold position 1021-1.

From network data terminal 996-1 and network data path segment 1034,FIG. 42:

branch data segment path 1072, FIG. 42, through hole 1073, branch datapath segment 1074, FIG. 43, to hole position 1022-1.

From network data terminal 996-2 and network data path segment 1045,FIG. 43:

branch data path segment 1081, FIG. 43, to hole position 1021-2: and

branch data path segment 1082, FIG. 43, to hole position 1022-2

The network power supply paths between connector positions 996-3 (CHG)and 996-4 (GND) and positions 995-3 and 995-4, respectively, are vianetwork power supply paths 1091, FIG. 43, and 1092, FIG. 42.

Branch power supply paths from network path 1091 to the various contactssuch as 991-3 are via through holes 1093, 1094 and 1095.

Branch power supply paths from network path 1092 are apparent at 1096and 1097, FIG. 42, for the leftmost contact of set 991 and for themiddle two holes of the four-hole row of hole pattern 1021.Corresponding power supply branch paths for contact sets 992 and 993 andfor hole pattern 1022 are apparent in FIG. 42.

A network direction control pathway is indicated at 1098, FIG. 42, andmay be coupled with branch paths such as 1099 (at the right in FIG. 43),when required, e.g. via through holes such as 1101 and 1102.

Discussion Re Claimed Subject Matter

FIG. 23 shows a series of docking receptacles 101-106 which are shown ingreater detail in FIG. 7. Preferred details of each docking receptaclewill be understood from the description of FIGS. 1-6, for example.

The docking receptacles have respective sets of docking terminals whichare engaged with contact means 471-476, FIG. 26, of the printed circuitboards 301, 302, FIGS. 25-27. The docking terminals may be formed byspring fingers 470, FIG. 27, which include protrusions 998, FIG. 27, forengaging the respective contact means 471-476, FIG. 26. Protrusions 998correspond with protrusion 63, FIG. 3, and contact mounting block 999,FIG. 27, may be identical to contact block 70, FIG. 3. Thus, the dockingconnectors 461-466, FIG. 25, may each correspond identically with theconnector assembly of FIG. 3, and may be associated with a respectivedocking receptacle 101-106, FIG. 23, as shown in detail in FIG. 5.

Referring to FIG. 41, the sets of docking terminals at couplinglocations 991, 992 and 993 may comprise data coupling terminals asrepresented at +485 and -485 in FIG. 41. Thus for an array of contactregions such as shown at 64 in FIG. 3, the third contact region fromeach end may provide a data coupling terminal. In a specificimplementation, these terminal positions +485 and -485 may connect withcorrespondingly located external contacts 80 in FIG. 2, and such contactpads 80 (i.e. the third and tenth such contact pads 80 in FIG. 2) may beconnected with the data lines of the third figure of the incorporatedapplication Ser. No. 07/339,330 (i.e. RS485 DATA+ line ninety-seven andRS485 DATA- line ninety-eight of the incorporated third figure.)

The docking terminals such as represented at 991-993, FIG. 41, mayfurther comprise power supply terminals such as CHG and GND, FIG. 41,which may contact the outermost pads 80, FIG. 2. The outermost pads 80(i.e. contact positions number one and number twelve) may connect with aline designated CHARGE in the third figure of the incorporatedapplication Ser. No. 07/339,330 (line number one hundred seven) and withthe power ground of the terminal. Referring to the sixth figure of theincorporated application Ser. No. 07/339,330, now abandoned, theoutermost pads 80 may be connected with the CHARGX line (designatedforty-three in the incorporated sixth figure) and with the BATT- linesassociated with the negative side of the terminal main battery(designated by reference numeral twenty-eight in the incorporated sixthfigure).

The printed circuit boards of each multidock such as 411, 412, 1007,987, 971-974 and 981-984, FIG. 40, may correspond with the printedcircuit boards 301, 302, FIGS. 25-27. Each such printed circuit boardmay be configured as represented in FIG. 41, so as to provide continuousstrips of electrically conductive material (e.g. copper) extendingbetween respective terminal positions of connectors 994,996 at one endof each board and respective corresponding terminal positions ofconnectors 995,997 at the opposite end of each board, to provide networkconductive path means. The network conductive path means are thencoupled with each set of docking terminals via branch conductive pathmeans such as branch data path means represented at 1006, 1007, FIG. 41,and branch power path means 1008, 1009, and which physically may includecontacts 471-476, FIG. 26, at the opposite side of boards 301 and 302from the network conductive strips, and through conductors extendingthrough the boards 301 and 302.

In FIGS. 34B and 34C, the lines from terminals A and B of differentialbus transceiver component 675 are designated 1011, 1012, and lead toprimary channel terminals 1014 and secondary channel terminals 1015,FIG. 34C.

The multidock 411, FIG. 40, may have its first printed circuit board(such as 301, FIGS. 25-26) connected with terminals 1014, FIG. 34C, viaa connector at position 450, FIG. 21, a suitable cable, and connector311, FIG. 25. The printed circuit board 301 may then provide rigidconductor network paths as represented in FIG. 41, extending adjacentthe sets of docking terminals at 461, 462, 463 from the end adjacentconnector 311, FIG. 25, to the end adjacent flex cable 303, FIG. 25. Theprinted circuit board 302 provides rigid conductor network paths asrepresented in FIG. 41 from the end adjacent flex cable 303, FIG. 25, tothe end adjacent connector 312, FIG. 25.

The secondary channel connectors 1015, FIG. 34C, may connect with anauxiliary power unit, e.g. at connector positions 1021, FIG. 32A.

A second printed circuit board such as 302 of a multidock such as 987,FIG. 40, may have its connector 312 coupled via a suitable cable withthe LAN Input indicated at 1022, FIGS. 32A and 32B. The LAN output 1023,FIG. 32A, would then connect with a connector such as 311, FIG. 25, of amultidock such as 971, FIG. 40.

The use of equipment such as represented in FIGS. 21, 23-27, 32A, 32B,34A-34C, 39, 40 and 41, enables a user to progressively increase dockingcapacity as needed e.g. by extending the network conductive path meanswith the use of further identical printed circuit boards, and tomaintain a neat, orderly and reliable system of interconnections. Anycomponent of the system is readily removed and replaced facilitatingservicing and minimizing downtime.

Referring to the specific example of FIGS. 23-27, 42 and 43, a series ofdocking receptacles (101-103 or 104-106, FIG. 23) has respective sets ofdocking terminals, e.g. 1121-1123, FIG. 23, for coupling with portabledata means (such as terminal 4, FIGS. 1, 2 and 6).

The printed circuit boards (such as 301, 302, FIGS. 23-27, and 990,FIGS. 42 and 43) have network conductive path means (such as networkdata path means 1034 and power supply path means 1092, FIG. 42, andnetwork data path means 1045 and power supply path means 1091, FIG. 43)on a rigid substrate 1130, FIGS. 42 and 43. The network conductive pathmeans extend past a multiplicity of the sets of docking terminals (e.g.past the three sets of docking terminals engaged with the contact sets991-993, FIG. 42).

As explained in reference to FIGS. 42 and 43, the network conductivepaths have branch conductive paths connecting the respective networkconductive paths with the respective docking terminals of the sets991-993. In FIG. 42, for example, network data path 1034 has branchpaths 1051, 1052, 1053, leading to printed conductive contact areas991-1, 992-1, and 993-1. These contact areas make electrical contactwith respective spring fingers forming the docking terminals viaprotrusions such as 63, FIG. 3. Power supply branch paths areexemplified by path 1096, FIG. 42.

The printed circuit boards 301, 322, FIGS. 25-27, provide rigidsubstrates having electrical connector means such as 311, 1131 (FIG.26), and 1132 (FIG. 26), 312 at the respective opposite ends forconnection of the conductive strips of the rigid substrate means asdescribed with reference to FIG. 40. The flex conductor 303 has flexibleconductive paths thereon as diagrammatically indicated at 303A in FIG.26 for connecting respective corresponding conductive strips of theprinted circuit boards 301 and 302.

The orderly use of printed circuit boards to provide the network dataand power supply paths leads to an optimum expandability and economy ofthe system while yet achieving a neat and compact arrangement withminimized opportunities for wiring errors during installation, or forinadvertent disturbance of wiring connections during use.

It will be apparent that many modifications and variations may beeffected without departing from the scope of the novel teachings andconcepts of the present invention.

The following pages show excerpts from a Product Specification for acommercial embodiment of auxiliary power unit in accordance with thepresent invention, and is designated herein as Exhibit A.

APPENDIX A

Excerpts from Sections 3.0 through 7.1 of a Product Specification ofNorand Corporation, Cedar Rapids, Iowa., concerning a Model 4970Auxiliary Power Unit, (All Copyright 1989 by Norand Corporation).

3.0 Product Overview

The Model 4970, Auxiliary Power Unit (APU) provides an extension to theNorand® 4000 Series system Local Area Network (LAN) for upto 24additional hand-held computers. The LAN is the physical data linkbetween Norand® 4000 Series Hand-Held computers and the Model 4980Network Controller. System components consist of the Model 4980 NetworkController, the Model 4970 Auxiliary Power Unit (APU), the Model 4960/50Communication Multidock/Single Dock, the 4300/4400 Series Hand-HeldComputers and the 4815 printer.

The LAN is a very high speed, serial data link implemented withtechnology complying to the Electronic Industries Association (EIA)RS-485 recommendation for a digital multipoint system. This physicallink allows the 4000 Series system to achieve a 500 Kbits per second(Kbps) data transfer rate over balanced, twisted pair cables. Themultidrop RS-485 technology and twisted pair cable media offer highernoise immunity than the traditional RS-232 technology, which results inallowable cable lengths of several thousand feet. Despite reliablecommunication capacity of RS-485 circuits over cables several thousandfeet in length, 4000 Series system cables are limited to less than 120feet to ensure reliable power transmission, regardless of the number ofhand-held computers in the system.

Flexible confirguration and installation are achieved in 4000 Seriessystems implementing the Model 4970 APU. The APU allows the network toexpand beyond the 24 terminals supported by a single Model 4980 NetworkController. The maximum 4000 Series network is achieved by installingtwo APUs, in addition to the Model 4980, permiting a total of 72hand-held computers on one local area network. The APU provides signalreconditioning, signal direction sensing and control, terminalcommunication power, and battery charging for a maximum of 24 Series4000 hand-held computers.

4.0 Equipment Specifications

Each of the following sections details Model 4970 performanceparameters.

4.1 Mechanical Specifications

4.1.1 Physical Dimensions

The mechanical enclosure has an overall maximum profile as specified bythe following measurements. The front surface slopes at 15.0 degreesfrom vertical with the bottom edge as the axis origin.

Depth: 8.10 inches (205.61 mm)

Width: 11.55 inches (293.37 mm)

Height: 10.58 inches (268.76 mm)

Weight: 4.7 pounds

4.1.2 Materials

The mechanical enclosure is comprised of two basic parts; the chassisand the front cover. The chassis provides the base for the enclosure,which houses the power supply, AC line filter, and D-Sub bracket. Thetop cover provides mounting for the printed circuit board. Finishingoverlays applied to the front cover seal cutouts and provide thecompleted 4000 Series look.

4.1.2.1 Chassis Material The chassis is made of 5052H32 aluminum, 0.063inch thick. Three brackets are required to complete the chassisassembly: Main Chassis (NPN 753-972-002) Left End Panel (NPN753-973-004) Right End Panel (NPN 699-167-004)

4.1.2.2 Top Cover Material The top cover is made of Borg Warner, ABS,Cycolac, KJU, 0.100 in. nominal thickness. The cover color is NPN560-500-001 (Light Gray). The cover is coated with a waterborne,conductive coating (NPN 901-398-001).

4.1.2.3 Overlay Material The overlays are made of hardcoated,polycarbonate film, 0.030 inch thickness. The backs are treated with3M-468 permanent acrylic adhesive. There are three overlays; the topoverlay (NPN 341-062-003), the 4000 Series identifier overlay (NPN341-062-001), and the Norand® Logo overlay, 0.010 inch thickness (NPN341-063-001).

4.1.3 Chassis Specifications The chassis consists of three parts; theright and left end panels and the main chassis bracket. The left endpanel provides mounting for the AC line filter. The main chassis bracketis a three sided structure which provides mounting for the AC-DC powersupply. The following sections detail the specifications for deviceswhich mount to or are supported by the chassis. The three chassisbrackets are assembled with # 4, 1/4 inch flat head screws.

4.1.3.1 AC-DC Power Supply (NPN 850-456-000) The power supply is an OEMproduct, which meets the electrical power requirements. The power supplyis encased in its own metal chassis, which provides two threadedmounting inserts for 4 mm screws. The power supply is mounted on avertical plane to the main chassis bracket. The overall moduledimensions are 7.4 inches (L)×3.75 inches (W)×2.0 inches (H). Themaximum allowable profile for the power supply is 8.0 inches (H)×5.0inches (W)×2.0 inches (H).

4.1.3.2 AC Power Entry Module (NPN 850-491-001) This module provides anInternational Electrotechnical Commission (IEC) power line inputconnector, which allows connection of universal power cords for domesticand international applications. The insulator box is a glass-filledthermoplastic (PETP) with a stamped and formed, aluminum shieldproviding a ground contact on the chassis mount. The module is installedon the left end panel of the main chassis. The same power entry moduleis used in both domestic and international configurations with only achange in wiring connections. The required mounting cutout dimensionsare 2.62 inches (H)×1.083 inches (W) with a 0.118 inch radius in eachcorner. The maximum interior depth required is 2.74 inches.

4.1.3.3 Mounting Facilities Both wall mount and free standinginstallations are provided in the chassis design. Wall mount studs areavailable on the back surface of the main chassis bracket. The studsinsert and lock into wall mount brackets (NPN 699-224-002). Freestanding installations are provided with the feet bracket (NPN753-975-002) and rubber feet (NPN 813-090-001) on the bottom of the mainchassis bracket. The mounting brackets are made of mild, cold rolledsteel, 12 MSG (0.1046 in.) thick.

4.1.4 Top Cover Specifications The top cover (NPN 641-357-001) is amolded component made of Borg Warner, ABS, Cycolac, KJU, 0.100 inchnominal thickness. The cover color is NPN 560-500-001 (Light Gray). Thiscover provides mounting for the printed circuit board, power-on LED, andthe D-Sub bracket. The inside of the cover is coated with a waterborne,conductive shield for enhanced EMI and Electrostatic Discharge (ESD)performance. Support posts for pressed nuts are provided for finalassembly to the chassis.

4.1.4.1 Printed Circuit Board Assembly (NPN 214-579-002) The printedcircuit board assembly is a raw board (NPN 144-376-003) fully loaded andtested with the components detailed in section 4.2.1. This assemblyincludes the D-Sub bracket (NPN 753-978-003).

4.2 Electrical Specifications

4.2.1 Model 4970 Printed Circuit Board Assembly (NPN 214-579-002) RawPrinted Circuit Board (NPN 144-376-003) The Model 4970 Auxiliary PowerUnit printed circuit board contains all the electronic componentsnecessary to provide the functionality, performance, and reliabilityrequired by the Product Design Specification (NPN 573-005-012). Thecircuit board contains functional circuits which are detailed in thefollowing sections. These circuits include the DC-DC converters, signaldirection sensing, and RS-485 serial interface. The total maximum powerrequirement of this printed circuit board assembly is 15 Volts @ 0.03Amperes (4.5 watts).

4.2.1.1 DC-DC Voltage Converter (NPN 333-047-000)

A +5 volt linear regulator supplies the logic voltage for the APUcircuitry. The +5 volt supply is produced by an LM-317T linearregulator. This regulator is capable of providing 1.5 amperescontinuously over the rated temperature. The maximum +5 volt requirementof the assembled circuit board is 300 mA.

4.2.1.2 RS-485 External Interface Drivers (NPN 310-505-000) The RS-485standard is defined by a differential signal between two dedicatedconductors. By utilizing the enhanced noise immunity and tolerance ofcommon mode voltages, RS-485 communication is capable of achieving datarates of 10 Mbits/Second over twisted pair cable lengths of 4000 feet.The RS-485 standard defines a multi-drop environment where a maximum of32 drivers and 32 receivers are allowed to operate on the same pair ofwires. The Norand Proprietary Communication Protocol (NPCP) has beendeveloped to resolve contention problems. The RS-485 transceiver chipsalso provide a level of contention protection by disabling the drivercircuit when line faults are sensed. Due to power limitations of theSeries 4000 system, practical cable lengths must be limited to less than1000 feet. Three 9-pin, female D-Sub, RS-485 output connectors areprovided externally. These connectors are designated as RS-485 outputsby the back panel silk screen. The three connectors are labeled LAN 1(Output), LAN 2 (Output), and LAN 2 (Input). LAN 2 (Input) is the entrypoint for the LAN which is to be extended. The connectors labeled asRS-485 Outputs are actually in parallel to the RS-485 transceiver withthe difference being a +15 volt supply provided to the LAN 1 Output forcommunication power to an immediate network. LAN 2 (Output) is intendedto provide a linking node for another Auxiliary Power Unit.

The following parameters define the performance of the physical RS-485interface on the Model 4980.

    ______________________________________                                        Functional Table (Driver)                                                     Input D  Enable DE     Output A Output B                                      (TXDA)   (RTSA)        (+485)   (-485)                                        ______________________________________                                        H        H             H        L                                             L        H             L        H                                             X        L             Z        Z                                             ______________________________________                                        Functional Table (Receiver)                                                   Differential Inputs                                                                            Enable RE                                                                              Output R                                            A-B              (DTRA)   (RXDA)                                              ______________________________________                                        V.sub.id ≧ 0.2 Volts                                                                    L        H                                                   -0.2 V < V.sub.id < 0.2 V                                                                      L        ?                                                   V.sub.id ≦ -0.2 V                                                                       L        L                                                   X                H        Z                                                   ______________________________________                                         H = High Level                                                                L = Low Level                                                                 ? = Indeterminate                                                             X = Immaterial                                                                Z = High Impedance                                                       

    Parameter                                                                            Min.    Typ.    Max   Units Conditions                                 ______________________________________                                        Driver Characteristic Specification                                           V.sub.IH                                                                             2.0                   volts                                            V.sub.IL               0.8   volts                                            |V.sub.OD |                                                                        4.0   volts I.sub.o = 0                                |V.sub.OD |                                                        2.0     2.25          volts R.sub.L = 100 Ω                      |V.sub.OD |                                                        1.5     2.0           volts R.sub.L = 54 Ω                       V.sub.OC               3.0   volts R.sub.L = 54 Ω or 100 Ω        I.sub.o                1.0   mA    V.sub.o = 12 Volts                         I.sub.o                -0.8  mA    V.sub.o = -7.0 Volts                       t.sub.plh      12      20    nS    R.sub.L = 27 Ω                       t.sub.phl      12      20    nS    R.sub.L = 27 Ω                       Receiver Characteristic Specification                                         V.sub.TH               0.2   volts V.sub.o = 2.7 Volts                                                           I.sub.o = -0.4 mA                          V.sub.TL                                                                             -0.2                  volts V.sub.o = 0.5 Volts                                                           I.sub.o = 8.0 mA                           V.sub.τ+ -V.sub.τ-                                                                   50            mVolts                                           V.sub.OH                                                                             2.7                   volts V.sub.ID = 200 mV                                                             I.sub.OH = -400 μA                      V.sub.OL                0.45 volts V.sub.ID = 200 mV                                                             I.sub.OH = 8.0 μA                       V.sub.OL                0.45 volts I.sub.OH = 16 μA                        I.sub.I                1.0   mA    V.sub.I = 12 Volts                         I.sub.I                -0.8  mA    V.sub.I = -7.0 Volts                       R.sub.l        12            kΩ                                         I.sub.OS                                                                             -15             -85   mA                                               t.sub.p lh     16      25    nS    V.sub.ID = -2.5 V to 25 V                  t.sub.phl      16      25    nS    C.sub.L = 15 pF                            ______________________________________                                    

The RS-485 signals are labeled as LAN outputs from the Model 4980.External connectors are 9-pin, female D-Sub connectors. The channels arelabeled on the chassis as Primary LAN and Auxiliary LAN, whichcorrespond to J6 and J7, respectively. The signal pinouts are:

    ______________________________________                                        Pin #         Mnemonic   Definition                                           ______________________________________                                        J6-1          +15 Volts  LAN Power                                            2             +485       Differential Signal (+)                              3             -485       Differential Signal (-)                              4             +15 Volts  LAN Power                                            5             Not Used                                                        6             Not Used                                                        7             GND        Signal Ground (Common Mode)                          8             GND        Signal Ground (Common Mode)                          9             Not Used                                                        J7-1          Not Used                                                        2             +485       Differential Signal (+)                              3             -485       Differential SignaI (-)                              4             Not Used                                                        5             Not Used                                                        6             Not Used                                                        7             GND        Signal Ground (Common Mode)                          8             GND        SignaI Ground (Common Mode)                          9             Not Used                                                        ______________________________________                                    

4.2.1.3 Directional Sensing and Control The LAN is a half-duplexenvironment (only capable of transmitting signals in one direction).Thus, an APU must provide the same signal direction l as the Model 4980Network Controller. Since the Model 4980 provides no directional controlsignal, the APU must ascertain signal direction on its own. This isachieved by monitoring the LAN activity and enabling the proper RS-485Driver.

4.2.2 Power Supply (NPN 850-456-000) The power supply is an AC to DCconverter that provides the electrical supply voltage to the Model 4970circuitry, and communication and terminal charging supply voltage to aprimary (LAN1) local area communication network. The power supply is anOEM product, which meets the following electrical requirements. ZincOxide Varistors (NPN 303-050-000) are connected to the AC input lines tothe power supply to protect the unit from line surge voltages. AC linevoltage surges greater than 340 volts will be suppressed (clamped) toprotect the power supply electronics. Input Voltage Range: 85 to 132Volts AC Input Frequency Range: 47 to 61 Hertz Input Current: 1.6Amperes (max.) Input Power: 135 Watts (max.) Inrush Current: 17 Amperes(Peak) Line Regulation: ±0.4% Volt Out over line voltage rangereferenced to nominal input voltage. Output Voltage: 15 Volts DC RatedOutput Current: 7 Amperes @ 50° C. Over Current Protection: Automaticcurrent limiting before 8 amperes. Output Ripple: 150 mVolts, Peak toPeak Load Regulation: ±0.4% Volt Out, No load to Full Load

4.2.3 Power Entry Module (NPN 850-491-001) Accessory Fuse Drawer (NPN850-491-101) Fuse (NPN 315-002-000) The power entry module is a 4 Amp ACRated line filter. This module provides an InternationalElectrotechnical Commission (IEC) power line input connector, whichallows connection of universal power cords for domestic andinternational applications. A double-pole, double-throw rocker switchallows the user to control AC power. The power line filter reduceselectromagnetic conducted (EMC) emissions from the power supply outthrough the power line cord. The filter circuit provides nearly 70 dBsignal attenuation over the frequency range of 10 to 100 MHz (Thegeneral range for FCC Part 15J conducted emissions testing). Aremoveable fuse drawer facilitates changing the line fuse withoutdisassembling the Model 4980 chassis. A 2 Amp, 250 VAC, fast acting, 3AGstyle fuse is used to match the AC requirements of the power supply.Power Entry Module Electrical Specifications: Voltage: 250 Volts AC(max.) Current: 4 Amperes (max.) @ 50° C. (At higher temperatures, theallowable maximum rated current decreases linearly to 0 Amps at atemperature of 85° C.) Leakage Current: 0.5 mA (250 VAC/50 Hz)Dielectric Withstand: 1500 VAC line to line, 2000 VAC line to caseAgency Approvals: UL, CSA, VDE and SEV (4 A/250 V) Fuse ElectricalSpecifications: Nominal Current: 2 Amps Voltage: 250 Volts InterruptCurrent: 10,000 Amperes @ 125 Volts AC 100 Amperes @ 125 Volts AC DCResistance: Less than 35 mΩ @ 2 Amperes Agency Approvals: UL Listed andCSA Certified Special Type Fuse (Class 1422-01)

4.3 Cable Specifications

4.3.1 Internal Cables All internal cables are designed for optimalelectrical performance, mechanical reliability, and ease of assembly.All wires are a UL recognized style. All cables are standard partslisted on the assembly bill-of-materials (NPN 225-374-XXX)

4.3.1.1 AC Power Supply Cables (NPN 216-551-XXX) Three cables provide ACpower connection from the power entry module to the AC/DC power supply.All wires are stranded, 18 gauge conductors with polyvinylchloride (PVC)insulation. Refer to the Model 4970, Auxiliary Power Unit assemblydrawing (NPN 225-373-001) for connection details.

4.3.1.2 DC Power Supply Cables (NPN 216-547-001) One cable assemblyconnects the DC output from the power supply to the printed circuitboard. A polarized connector terminates the connection made to thecircuit board simplifying assembly and ensuring proper DC voltagepolarity. All wires are 18 gauge conductors with PVC insulation.

    ______________________________________                                        Pin #         Definition                                                                             Color                                                  ______________________________________                                        1             Ground   Black                                                  2             +15 V    White                                                  ______________________________________                                    

4.3.1.5 LED Cable (NPN 216-XXX-001) One cable assembly provides theelectrical interface between the printed circuit board and the power-onLED mounted on the top cover. Both cable connectors are polarized. Bothwires are 22 gauge, PVC, stranded wire.

4.3.2 External Cables All external cables are designed to provide thehighest EMI and ESD protection. All cables are shielded and terminatedto the connector D-Sub housing. In cases where devices with separate ACpower supplies are connected, the cable shield is terminated at theModel 4970 end only. This is done to reduce ground loop currents.Reference the Norand specification on Shielded Cable Assembly Procedure(NPN 440-001-001). All external cables are standard parts under theassembly bill-of-materials (NPN 225-374-XXX).

4.3.2.1 RS-485 LAN Cable (NPN 216-601-XXX) This cable interconnects theRS-485 ports on the Model 4980 Network Controller, the Model 4970Auxiliary Power Unit, and the Model 4960 Multidock. This provides thephysical LAN and is a shielded, twisted-pair cable. The three digitindex of the part number selects the cable length. The following drawingillustrates the logical signal connections between RS-485 ports.

    ______________________________________                                        Model 4980                     Model 4980                                     RS-485                         RS-485                                         Pin Number                     Pin Number                                     ______________________________________                                        1 #STR9##                                                                     2 #STR10##                                                                    3 #STR11##                                                                    4 #STR12##                                                                    ______________________________________                                    

4.3.2.1 AC Power Cable (NPN 321-054-001) The AC power cable provides areliable and safe entry path for AC power. The power cable has a moldedIEC type termination, which mates to the power entry module of the Model4970. The other end of the power cable is terminated for connection to agrounded, three-prong style AC power outlet. The cable has a foil shieldand copper braid to provide suppression of EMI and EMC energy. AC PowerCable Specifications Maximum Voltage Rating: 125 VAC (minimum) MaximumCurrent Rating: 10 Amperes (minimum) Copper Braid Shield: 85% coverageFoil Shield: 100% coverage Conductors: 3 Conductors @ 41 gauge strandedwire. Agency Certifications: UL and CSA

4.4 Environmental Specifications The Model 4970 Auxiliary Power Unitmeets all performance specifications over the range of environmentalconditions defined in this section. All specifications have beenverified according to Quality Assurance Environmental Testing Procedures(NPN 435-000-059, Rev. D). The Model 4970 is categorized as a type Dproduct (stationary, portable, table-top operation). When any specifiedenvironmental condition is violated, operational performance and lifeexpectancy of this product are compromised.

4.4.1 Operating Temperature High Operating Temperature: 50° C. (122° F.)Low Operating Temperature: 0° C. (32° F.) Reference NPN 435-000-059,Rev. D, Section 5.2 and 5.3 for operating temperature test procedure andpass/fail criteria.

4.4.2 Storage Temperature High Storage Temperature: 70° C. (158° F.) LowStorage Temperature: -30° C. (-22° F.) Reference NPN 435-000-059, Rev.D, Section 5.4 and 5.5 for storage temperature test procedure andpass/fail criteria.

4.4.3 Humidity Relative Humidity: Up to 95% noncondensing Reference NPN435-000-059, Rev. D, Section 5.7 for operating test procedure andpass/fail criteria.

4.4.4 EMI/EMC The Model 4970 Auxiliary Power Unit will not radiate orconduct electromagnetic emissions in excess of the level described bythe FCC Part 15, Subpart J, Class A Standard for computing devices.

4.5 Durability Specifications The Model 4970 Auxiliary Power Unit meetsall performance specifications over a specific range of externalphysical conditions. All specifications have been verified according toQuality Assurance Environmental Testing Procedures (NPN 435-000-059,Rev. D). When any specified condition is violated, operationalperformance and life expectancy of this product are compromised.

4.5.1 Electro-Dynamic Random Vibration This simulates 1,000 miles ofbasic, common-carrier transportation for every hour of test. Althoughrarely encountered in normal operation, all Norand products aresubjected to random vibrations regardless of where or how they are used.Reference NPN 435-000-059, Rev. D, Section 8.5 for operating testprocedure and pass/fail criteria. Amplitude: 1.04 grams RMS (verticalaxis) 0.20 grams RMS (transverse axis) 0.74 grams RMS (longitudinalaxis) Frequency Range: 500 to 1500 cpm (cycles per minute) Sweep time: 1minute Duration: 6 hours

4.5.2 Electro-Dynamic Quasi-Random Vibration Quasi-random vibrationtesting is a form of stress screening where vibrations are randomlyinduced on all three axes. This test identifies weaknesses in theproduct that occur due to extreme temperature change and vibrationconditions. Reference NPN 435-000-059, Rev. D, Section 8.6 for operatingtest procedure and pass/fail criteria. Amplitude: 1.5 grams RMSTemperatures: 0° C., 50° C. Duration: 6 hours

4.5.2 Protected Drop

This test simulates handling that occurs during transportation. Thepackaging is adequate such that a drop from 36 inches on any surface oredge will not damage the product contained within the package. ReferenceNPN 435-000-059, Rev. D, Section 9.1 for test procedure and pass/failcriteria.

4.5.3 Unprotected Drop Stationary, portable products are most subject todrops from table top heights. This drop test verifies productfunctionality after a drop from thirty inches onto a plywood platform.Reference NPN 435-000-059, Rev. D, Section 9.2 for test procedure andpass/fail criteria.

4.5.4 Electrostatic Discharge (ESD) Performance is unaffected by anyelectrostatic discharge to any exterior surface or attachable cord. TheModel 4970 is described as a Class B device for ESD protection. A ClassB device is intended for a "typical environment" as detailed in theEngineering Special Report for ESD Test Standards (NPN 568-004-010).Test procedures are described in the "ESD Test Guidelines" specification(NPN 578-004-003). ESD Level: 20 KVolts minimum

4.5.5 Mean Time Between Failures (MTBF) The MTBF is the expectedoperational life time of the product under normal usage withoutexceeding any environmental conditions. Calculated: 88,751 Power OnHours (POH) Tested: To Be Determined

4.6 Agency Certifications

4.6.1 Underwriters Laboratories (UL) The Model 4970 Auxiliary Power Unitis certified by Underwriters Laboratories under the UL-478 Standard forelectronic devices.

4.6.2 Federal Communications Commission (FCC) The Model 4970 AuxiliaryPower Unit is certified by the Federal Communications Commission underthe FCC Part 15, Subpart J, Class A Standard for computing devices.

5.0 Installation Specification

Proper installation of the Model 4970 Auxiliary Power Unit protects alldevices in the system and promotes maximum system performance and life.Installation instructions are available in the Network ControllerInstallation Instructions (NPN 962-028-004).

5.1 Mechanical Installation

5.1.1 Wall Mount Installation Wall mount brackets (NPN 699-224-002) areavailable for wall surface installations. Studded posts on the rear ofthe chassis insert into slots on the wall mount brackets and slide intoplace as the chassis is lowered into place. When properly installed, thewall mount brackets are concealed. Wall mount brackets must be securelyfastened to the wall. The brackets will be required to support 9 pounds.Two brackets are required to install the Model 4980. The brackets shouldbe installed on 6 inch centers. Ensure that the brackets are parallel toeach other and provide a level mounting platform.

5.1.2 Table Top (Free Standing) Installation Rubber feet provide anon-skid platform base for the Model 4970 chassis. Internal componentshave been distributed evenly to create a low center of gravity. Theinstallation surface should be level and completely clear of non-systemequipment.

5.2 Electrical Installation

5.2.1 Cable Installation

5.2.1.1 RS-485 Connectors The external RS-485 ports have 9-pin, femaleD-Sub connectors. Latching posts are provided with each connector.Cables are attached with clip latches provided on the connector housingof the cable.

5.2.1.2 AC Power Cable (NPN 321-054-001) The AC power cable is insertedinto the receptacle provided in the power entry module on the left sideof the Model 4970. The power cable is a detachable, IEC type. Completeinsertion must be made for reliable operation. Refer to the NetworkController Installation Instructions (NPN 962-028-004) for AC powersystem requirements.

6.0 General Operational and Procedures

Once the system is correctly configured and all cables properly secured,the Model 4970 is ready for operation. This section describes theprocedure for powering up the Model 4970.

6.1 Power Up Sequence The rocker switch of the power entry module istoggled to the on-line position. The power LED eluminates. Any terminalsinserted into attached Multidocks receive transmission circuit power andwill "wake-up".

7.0 Compatibility Specification

7.1 The Model 4970 is designed to service the Series 4000 Local AreaNetwork. It is to be integrated into systems as a support device for theModel 4980 Network Controller only.

I claim as my invention:
 1. A system for transmitting data to and from a plurality of portable data entry terminals, the system comprising:a plurality of data communication sub-systems each comprising:(a) local area network including a controller and a common data communication link interconnecting a plurality of data transfer points that transmit data between each of the plurality of data transfer points and the local area network over shared portions of the common data communication link, each data transfer point adapted to be coupled to any one of the plurality of portable data entry terminals for data transfer via the common data communication link; (b) a plurality of docking units, one for each of the plurality of data transfer points, each one of the plurality of docking units having a receptacle constructed to receive and retain therein any one of the plurality of portable data entry terminals and a data coupler connected to the one data transfer point corresponding to the one docking unit and arranged for coupling with any one of the plurality of portable data entry terminals upon being received therein such that data transfer with the local area network is carried out via said coupled data transfer point and the common data communication link; and (c) the controller coupling with the common data communication link to control data transfer between the local area network and any one of the plurality of portable data entry terminals when received by the corresponding one docking unit and one data transfer point; and a central controller providing communication between a respective controller of each of the plurality of data communication sub-systems and a central data link.
 2. The system of claim 1, wherein the central controller further comprises circuitry that assigns a unique address to a portable data entry terminal when coupled to one of the plurality of docking units.
 3. The system of claim 1 wherein each of the plurality of data transfer points is constructed to be coupled to any one of the plurality of portable data entry terminals.
 4. The system of claim 1, wherein at least one of the data communication sub-systems further comprises a terminal controller that has quick release signal coupling with the common data path of the local area network to accommodate removal of any of the plurality of portable data terminals from the local area network for independent operation remote therefrom.
 5. The system of claim 1, further comprising a host computer, the central controller providing a transparent communication path between the host computer and the plurality of portable data entry terminals.
 6. In a system for gathering data, a plurality of portable data entry terminals, each data entry terminal having an array of terminal contacts,at least one unit, said unit comprising an aligned arrangement of docking receptacles, each of said docking receptacles having a like array of receptacle contacts, each of said docking receptacles adapted to receive one of said data entry terminals such that corresponding ones of said arrays of terminal and receptacle contacts mate with each other upon loading one of said data entry terminals into any one of said docking receptacles, said unit having electrical conductive means for transmitting data signals to and from each of said inserted data entry terminals and for providing electrical power signals to each of said inserted data entry terminals, said electrical conductive means comprising a set of main conductive paths, each main conductive path extending adjacent said arrangement of docking receptacles and continuously from a first end of said main conductive paths to a second end thereof, and a plurality of sets of branch conductive paths, one set of branch conductive paths for each of said docking receptacles, each branch conductive path extending continuously from one of said main conductive paths to a corresponding one of said receptacle contacts of its docking receptacle for providing distinct connection to each receptacle contact of its docking receptacle and for transmitting data from a loaded one of said plurality of portable data entry terminals via at least one terminal contact of said transmitting portable data entry terminal to a corresponding receptacle contact of each docking receptacle of said alignment arrangement.
 7. In a data gathering system as claimed in claim 6, said unit further comprising common substrate means of elongated configuration with opposing ends, and connector means disposed at least one of said opposing ends, said main conductive paths disposed on said common substrate means and interconnected with said connector means.
 8. In the data gathering system as claimed in claim 7, wherein said common substrate means comprises printed circuit board means.
 9. In a data gathering system as claimed in claim 8, wherein said printed circuit board means mounts said arrangement of docking receptacles thereon. 